(The Conversation) – Cyclone Chido was an “intense tropical cyclone”, equivalent to a category 4 hurricane in the Atlantic. It made landfall in Mayotte, a small island lying to the north-west of Madagascar on December 14, generating wind gusts approaching 155mph (250km/hr). Later on, it hit Mozambique, East Africa with the same ferocity.

This storm skirted north of Madagascar and affected the Comoros archipelago before making landfall in Mozambique. It is well within the range of what is expected for this part of the Indian Ocean. But this region has experienced an increase in the most intense tropical cyclones in recent years. This, alongside its occurrence so early in the season, can be linked to increases in ocean temperatures as a result of climate change.

News of the effects of tropical cyclone Chido in Mayotte, Mozambique and Malawi continues to emerge. Current estimates suggest 70% of Mayotte’s population have been affected, with over 50,000 homes in Mozambique partially or completely destroyed.

Ongoing conflict in Mozambique and undocumented migration to Mayotte will have played a key role in the number of deaths and the infrastructure damage.

Assessing how these cyclones characteristics are changing across southern Africa is part of the research we are involved in. Our team also studies how to build resilience to cyclones where conflict, displacement and migration magnify their effects.

A human-made disaster?

The risk that tropical cyclones pose to human life is exacerbated by socioeconomic issues. Migrants on Mayotte, many of whom made perilous journeys to escape conflict in countries such as the Democratic Republic of Congo, now make up more than half of the island’s population.

Precarious housing and the undocumented status of many residents reportedly made the disaster more deadly, as people feared evacuation would lead them to the police. On islands with poor infrastructure such as Mayotte, there is often simply nowhere safe to go. It takes many days for the power network and drinking water supply to be restored.

The situation is particularly complex in Mozambique. The ongoing conflict and terrorist violence, coupled with cyclones, including Kenneth in 2019, has caused repeated evacuations and worsening living conditions. Cabo Delgado and Nampula in the far north of Mozambique, the provinces most affected by both Chido and the conflict, rank among the poorest and most densely populated in the country due to limited education, scarce livelihood options and an influx of people displaced by violence.

“Chido Strikes Maputo,” Digital, Dream / Dreamland v3 / Clip2Comic / IbisPaint, 2024 based on photo by Mister Paps on Unsplash

As of June 2024, more than half a million people remained without permanent homes in the region, many living in displacement camps. That number is likely to rise significantly after Chido.

Compounding the crisis, Chido’s landfall so early in the cyclone season meant that the usual technical and financial preparations were not yet fully ramped up, with low stock levels delaying the timely delivery of aid. Unrest following elections in November hampered preparations further, cutting the flow of resources and personnel needed for anticipatory action and early response.

Tropical cyclones in a warmer world

Warmer sea surface temperatures not only provide more fuel for stronger storms, but may also expand the regions at risk of tropical cyclones.

The Indian Ocean is warming faster than the global average, and is experiencing a staggering increase in the proportion of storms reaching the intensity of Chido.

Climate simulations predict that storms will continue getting stronger as we further warm our world, and could even lead to an unprecedented landfall as far south as the Mozambican capital, Maputo.

Scientists carry out attribution studies to determine how climate change contributed to specific events. Scientists undertaking rapid attribution studies of Chido have found that the ocean surface temperatures along the path of the storm were 1.1°C warmer than they would have been without climate change. So, temperatures this warm were made more than 50 times more likely by climate change. Another study focusing on Chido itself concluded that the cyclone’s winds were 5% faster due to global heating caused by burning fossil fuels, enough to bump it from a category 3 to a category 4 storm.

Intense winds are not the only hazard. Scientists are confident that tropical cyclones will dump more rain as a result of climate change. A trend towards slower-moving storms has been observed, causing more of that rain to accumulate in a single location, resulting in floods.

Cyclone Freddy delivered a year’s worth of rain to southern Malawi in just four days in March 2023. Storm surges, exacerbated by sea level rise, also raise the scale of flooding, as in the devastating Cyclone Idai in March 2019. An increase in the number of storms that rapidly intensify, as Chido did before landfall in Mayotte has also been linked to climate change, which makes it harder to provide early warnings.

To improve resilience to future cyclones, conflict, migration and social dynamics must be considered alongside climate change, without this, displaced and migrant communities will continue to be the most affected by the risks that climate change poses.

Liz Stephens, Professor of Climate Risks and Resilience, University of Reading; Dan Green, PhD Candidate in African Climate Science, University of Bristol, and Luis Artur, Lecturer and Researcher of Disaster Risk Reduction, Universidade Eduardo Mondlane

This article is republished from The Conversation under a Creative Commons license. Read the original article.

At its most violent, Chido had winds of 150 miles per hour, and was still going nearly 140 miles an hour when it hit Mayotte. Huts, tin shanties, and bungalows offered no shelter at all from this juggernaut.

The Grantham Institute at Britain’s Imperial College estimated that human-caused climate change has made it 40% more likely that a tropical cyclone such as Chido would move from a Category 3 (11–129 miles per hour) to a Category 4 (130–156 miles per hour) on the Saffir-Simpson Hurricane Wind Scale. That is, the average global surface temperature is now 2.34º F. (1.3º C.) higher than in the late 1700s before the Industrial Revolution put all that carbon dioxide into the atmosphere by burning coal (and later petroleum and fossil gas). That extra heat makes the Indian Ocean hotter, and hot ocean waters create and turbocharge cyclones (called “hurricanes” in the Atlantic). Hot waters also put more moisture into the atmosphere, causing massive downpours of the sort that struck Mayotte. The scientists at the Grantham institute warn that if we heat the world up by 4.68º F. (2.6º C.) above the average of the late 1700s, cyclones like Chido will be 66% more likely to move from a Cat 3 to a Cat 4.

Seriously, I don’t know how people expect to have civilization if we do that, i.e. if we don’t stop burning gasoline and coal right now. France is able to establish an emergency airlift of food and supplies to Mayotte from Réunion off the coast of Madagascar, without which there would be mass starvation within 4 days. But what if hurricanes even more powerful than Chido hit Réunion and Mayotte at the same time? Repeatedly?

I lived in the Horn of Africa when I was a teenager, and it gave me an interest in the region. If you come down the coast of West Africa, Kenya gives way to Tanzania below Mombasa. And then just south of Mtwara you come to the border with Malawi. And if you got on a ship there and went out a little southeast, you’d come to the Comoros islands (in Arabic, jaza’ir al-qamar or Islands of the Moon). Comoros is an independent country now, consisting of three islands. It is a former French colony that became independent in 1975 and is a member of the Arab League.

But a fourth island, Mayotte, might have become part of Comoros in the age of decolonization in the 1970s. The people there instead voted to remain part of France, and they are now recognized as an overseas département. When you’re part of France, you’re part of France, no matter if you are out on the edge of Africa facing the Indian Ocean. They have a deputy in the French National Assembly and two senators. Puerto Rico should be so lucky.

French President Emmanuel Macron even came for a visit on Thursday.

The 320,000 people there are mostly Sunni Muslims of Bantu heritage and their language descends from Swahili (Arabic for the “coastal language”). There are a few Roman Catholics. About 20% of the population has good French, essential for getting a government job. There may be 100,000 undocumented migrants — people come from the Comoros to Mayotte hoping it will be a launching pad for getting into France.

It is tempting to see what happened to Mayotte as a fluke, and to see the suffering there as that of a distant and exotic people. But islands and coastal areas being flattened by hurricanes is going to become more and more common, and future storms will be even more destructive. This cosmopolitan member of the Islands of the Moon is trying to tell us something. We should listen.

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Bonus Video:

French Mayotte cyclone’s toll still unclear as authorities ramp up response • FRANCE 24 English

(The Conversation) – Two years ago, when the curtain fell on the COP27 summit in Sharm El Sheikh, Egypt, developing nations on the frontline of climate change had something meaningful to celebrate.

The creation of a new fund for responding to loss and damage was agreed after a hard-fought diplomatic effort, spearheaded by a group of small island developing states (sometimes known as the Sids). The fund would provide much needed support for climate-vulnerable nations faced with a spiralling human and financial toll from sea-level rise, extreme temperatures, droughts, wildfires, and intensifying floods and storms.

Yet two years on, the world’s wealthiest nations – also the largest carbon emitters – are still dragging their feet. They’ve not followed up their pledges with anywhere near the finance required.

Some nations, particularly the 39 Sids, which include places like Barbados, Grenada, Fiji and Vanuatu, are uniquely vulnerable to climate change and are already paying the price.

Sky-high ocean temperatures created the conditions for Hurricane Beryl to develop in July this year, as the earliest-forming Category 5 hurricane on record in the Caribbean. As oceans warm up, climate science tells us that this rapid intensification is becoming more common.

The island nation of Fiji, best known as a tropical paradise, has experienced a frightening series of storms over recent years, linked to climate change. Cyclone Winston in 2016, one of the most intense on record, caused widespread flooding and lead to the loss of 44 lives.

This episode reduced Fiji’s GDP growth by 1.4 percentage points. According to the Asian Development Bank, ongoing losses from climate change could reach 4% of Fiji’s annual GDP by 2100, as higher temperatures and more extreme weather hold back growth.

This isn’t an isolated problem. Tropical cyclones and hurricanes have long battered small islands, but what is new is how often the most extreme storms and floods are happening, as well as our improved ability to measure their economic effects.

Direct and indirect impacts

Our latest research looked at extreme weather events affecting 35 small island developing nations. We first collected information about the direct consequences of these extreme weather events: the damaged homes, the injured people, and the bridges that must be rebuilt.

We then looked at how these events have affected GDP growth and public finances. These changes are not felt immediately, but rather as the economy stalls, tourism dries up, and expensive recovery plans inhibit spending in other areas.

In all, from 2000 to 2020, these direct and indirect impacts may have cost small island states a total of US$141 billion. That works out to around US$2,000 per person on average, although this figure underplays just how bad things can get in some places. Hurricane Maria in 2017 caused damage to the Caribbean island of Dominica worth more than double its entire GDP. That amounted to around US$20,000 per person, overnight. Almost a decade later, the country is still struggling with one of the largest debt burdens on earth at over 150% of GDP.

Of these huge aggregate losses across all the small island development states, around 38% are attributable to climate change. That’s according to calculations we made based on “extreme event attribution” studies, which estimate the degree to which greenhouse gas emissions influenced extreme weather events.

“Fiji Superstorm,” Digital, Midjourney / Clip2Comic, 2024

What is clear is that small island economies are among the worst affected by severe weather. These island states have three to five times more climate-related loss and damage than other states, as a percentage of government revenues. That’s true even for wealthier small island states, like the Bahamas and Barbados, where loss and damage is four times greater than other high-income countries. For all small island nations, the economic impacts will increase, with “attributable” losses from extreme weather reaching US$75 billion by 2050 if global temperatures hit 2°C above pre-industrial levels.

Our research helps us to see how far short the richer nations driving climate change are falling in their efforts to both curb emissions and to compensate the nations harmed by their failure to prevent climate change.

Developed countries need to pay up

One of the key discussions at the forthcoming COP29 climate summit in Baku, Azerbaijan, will be the “new collective quantified goal”. This is the technical name to describe how much money wealthy countries will need to contribute to help vulnerable nations to mitigate and adapt to climate change.

That overall goal must also include a target to finance small islands and other vulnerable countries, with billions more needed per year in the new loss and damage fund. Given the extent of actual and likely losses, nothing less than ambition on the scale of a “modern Marshall Plan” for these states will do.

In addition to this extra financing, the fund will need to work effectively to support the most climate vulnerable nations and populations when severe weather occurs. This can be done in a few ways.

The fund could create a budget support mechanism that can help small island states and other vulnerable countries deal with loss of income and the negative effects on growth. It could make sure loss and damage funds can be released quickly, and ensure support is channelled to those who need it the most. It could also make more concessional finance available for recovery, especially for the most adversely affected sectors like agriculture and tourism.

The world has a troubling history of missing self-imposed targets on climate finance and emissions reduction. But the stakes are ever higher now, and any target for loss and damage finance will need to be sufficient to deal with the challenges posed already by climate change, and in the years to come.

Emily Wilkinson, Principal Research Fellow, ODI Global; Ilan Noy, Chair in the Economics of Disasters and Climate Change, Te Herenga Waka — Victoria University of Wellington; Matt Bishop, Senior Lecturer in International Politics, University of Sheffield, and Vikrant Panwar, Senior Climate and Disaster Risk Finance Specialist, ODI Global

This article is republished from The Conversation under a Creative Commons license. Read the original article.

(The Conversation) – In the last few days, a seasonal weather system known in Spain as the “cold drop” or DANA (an acronym of depresión aislada en niveles altos: isolated depression at high levels) has caused heavy rain and flooding across Spain’s Mediterranean coast and in Andalusia, especially in the Valencian Community, Castilla-La Mancha and the Balearic Islands. The storm has left hundreds dead and many more missing, with immense damage in the affected areas.

50 years ago, a DANA occurred every three or four years, typically in November. Today, they can happen all year round.

How does a DANA form?

These storms are formed in the same way as Atlantic hurricanes or typhoons in China. The difference is that the Mediterranean is smaller than these areas, and so storms have a shorter path, and store less energy and water vapour.

Decades ago, warm sea surfaces at the end of summer would cause water to evaporate into the atmosphere. Today, the sea surface is warm all year, constantly sending massive amounts of water vapour up into the atmosphere.

The poles are also much warmer now than they were 50 years ago. As a result, the polar jet stream – the air current that surrounds the Earth at about 11,000 metres above sea level – is weakened and, like any slowly flowing current, has meanders. These bring cold air, usually from Greenland, into the high atmosphere over Spain.

The evaporated water rising off the sea meets this very cold air and condenses. The Earth’s rotation causes the rising air to rotate counterclockwise, and the resulting condensation releases huge quantities of water.

This combination of factors causes torrential, concentrated rains to fall on Spain, specifically on the Balearic Islands and the Mediterranean coast, sometimes reaching as far inland as the Sierra de Segura mountains in Andalucia and the Serrania de Cuenca mountains in Castilla la Mancha and Aragón. These storms can move in very fast, and are extremely violent.

On occasions, this Mediterranean water vapour has moved as far as the Alps, crossing its western point and causing downpours in Central Europe.

Warming oceans, warming poles

Many years ago, humans discovered a gigantic source of energy: 30 million years worth of the sun’s energy, stored under the ground by plants and animals. Today, we are burning through this resource fast.

This fossilised energy source is made up of carbon compounds: coal, hydrocarbons and natural gas. By burning them, we release polyatomic molecules such as carbon dioxide, methane, nitrogen oxides and other compounds. Once released into the atmosphere, these trap some of the heat radiating from the earth’s soil and seas, returning it to the planet’s surface.

This process is what causes climate change, and it can occur naturally. When these molecules, especially methane, are stored in continental ocean slopes, the water cools and the carbon dioxide captured by the waves is trapped inside. As the planet cools and sea levels fall, methane is eventually released into the atmosphere. The atmosphere warms up, warming the sea, and the sea releases CO₂ which amplifies the effect of the methane. The planet then gets warmer and warmer, causing glaciers to melt and sea levels to rise.

This alternation of cold and hot has occurred eight times over the last million years.

No end in sight for fossil fuels

Today we are forcing this process by emitting huge quantities of polyatomic gases ourselves. The question is whether we can limit these emissions. So far, this has been impossible.

To this we can add the fact that by 2050 there will be about two billion more human beings on the planet, who will also need food, housing and transport. This means more chemical fertilisers, cement, petrol, diesel and natural gas will be consumed, leading to further polyatomic gases being released.

Various measures to limit the burning of carbon compounds are falling short, or developing very slowly. Hopes for electric cars, for example, have been greatly diminished in recent years.

In Europe progress is being made in solar and wind energy, but electricity only makes up around a third of the energy consumed. Europe is also the only region making real progress on alternative electricity generation – much of China’s progress is being offset by its continued construction of coal-fired power plants.

Despite some large, high-profile projects, the reality is that we will continue to burn carbon compounds for many decades to come. This means the concentration of polyatomic gases in the atmosphere will increase over the next century, and with it the temperature of the planet, leading to more DANAs, hurricanes, typhoons and floods.

Climate adaptation is vital

What we are left with is adaptation, which is much more manageable as it does not require international agreements.

In Spain, for instance, we can control flooding through massive reforestation in inland mountainous areas, and through rainwater harvesting systems – building small wetlands or reservoirs on hillsides. This would slow the amount of water reaching the ramblas and barrancos, the gorges and channels that funnel rainwater through Spain’s towns and prevent them from flooding. At the same time, this would mean water can be captured by the soil, where it can then be gradually returned to the rivers and reservoirs.

Not only is this feasible, it is cost-effective, generates many jobs, and could save hundreds, if not thousands of lives.

Antonio Ruiz de Elvira Serra, Catedrático de Física Aplicada, Universidad de Alcalá

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Bonus video added by Informed Comment:

AP: “Climate change is making extreme downpours in Spain heavier and more likely, scientists say”

(The Conversation) – Hurricane Milton went from barely hurricane strength to a dangerous Category 5 storm in less than 24 hours as it headed across the Gulf of Mexico toward Florida.

As its wind speed increased, Milton became one of the most rapidly intensifying storms on record. And with 180 mph sustained winds on Oct. 7, 2024, and very low pressure, it also became one of the strongest storms of the year.

Less than two weeks after Hurricane Helene’s devastating impact, this kind of storm was the last thing Florida wanted to see. Hurricane Milton was expected to make landfall as a major hurricane late on Oct. 9 or early Oct. 10 and had already prompted widespread evacuations.

So, what exactly is rapid intensification, and what does global climate change have to do with it? We research hurricane behavior and teach meteorology. Here’s what you need to know.

What is rapid intensification?

Rapid intensification is defined by the National Weather Service as an increase in a tropical cyclone’s maximum sustained wind speed of at least 30 knots – about 35 mph within a 24-hour period. That increase can be enough to escalate a storm from Category 1 to Category 3 on the Saffir-Simpson scale.

Milton’s wind speed went from 80 mph to 175 mph from 1 p.m. Sunday to 1 p.m. Monday, and its pressure dropped from 988 millibars to 911.

The National Hurricane Center had been warning that Milton was likely to become a major hurricane, but this kind of rapid intensification can catch people off guard, especially when it occurs close to landfall.

Hurricane Michael did billions of dollars in damage in 2018 when it rapidly intensified into a Category 5 storm just before hitting near Tyndall Air Force Base in the Florida Panhandle. In 2023, Hurricane Otis’ maximum wind speed increased by 100 mph in less than 24 hours before it hit Acapulco, Mexico. Hurricane Ian also rapidly intensified in 2022 before hitting just south of where Milton is projected to cross Florida.

What causes hurricanes to rapidly intensify?

Rapid intensification is difficult to forecast, but there are a few driving forces.

• Ocean heat: Warm sea surface temperatures, particularly when they extend into deeper layers of warm water, provide the energy necessary for hurricanes to intensify. The deeper the warm water, the more energy a storm can draw upon, enhancing its strength.

• Low wind shear: Strong vertical wind shear – a rapid change in wind speed or direction with height – can disrupt a storm’s organization, while low wind shear allows hurricanes to grow more rapidly. In Milton’s case, the atmospheric conditions were particularly conducive to rapid intensification.

• Moisture: Higher sea surface temperatures and lower salinity increase the amount of moisture available to storms, fueling rapid intensification. Warmer waters provide the heat needed for moisture to evaporate, while lower salinity helps trap that heat near the surface. This allows more sustained heat and moisture to transfer to the storm, driving faster and stronger intensification.

• Thunderstorm activity: Internal dynamics, such as bursts of intense thunderstorms within a cyclone’s rotation, can reorganize a cyclone’s circulation and lead to rapid increases in strength, even when the other conditions aren’t ideal.

Research has found that globally, a majority of hurricanes Category 3 and above tend to undergo rapid intensification within their lifetimes.

How does global warming influence hurricane strength?

If it seems as though you’ve been hearing about rapid intensification a lot more in recent years, that’s in part because it’s happening more often.

A 2023 study investigating connections between rapid intensification and climate change found an increase in the number of tropical cyclones experiencing rapid intensification over the past four decades. That includes a significant rise in the number of hurricanes that rapidly intensify multiple times during their development. Another analysis comparing trends from 1982 to 2017 with climate model simulations found that natural variability alone could not explain these increases in rapidly intensifying storms, indicating a likely role of human-induced climate change.

How future climate change will affect hurricanes is an active area of research. As global temperatures and oceans continue to warm, however, the frequency of major hurricanes is projected to increase. The extreme hurricanes of recent years, including Beryl in June 2024 and Helene, are already raising alarms about the intensifying impact of warming on tropical cyclone behavior.

Zachary Handlos, Atmospheric Science Educator, Georgia Institute of Technology and Ali Sarhadi, Assistant Professor of Atmospheric Science, Georgia Institute of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

(The Conversation) – Hurricane Helene caused deadly and destructive flooding when it swept through the Southeast on Sept. 26-29, 2024. Across a broad swath of western North Carolina, where the worst flooding occurred, the amount of rainfall exceeded levels that would be expected on average only once every 1,000 years.

But this wasn’t the first 1,000-year rainstorm in North Carolina this year. In mid-September, an unnamed slow-moving storm produced more than a foot of rainfall closer to the Atlantic coast. This storm inundated areas that had already been drenched by Tropical Storm Debby in August.

As atmospheric scientists and state climatologists, we believe it’s important for the public to understand the risk that extreme events may occur. That’s especially true as climate change alters the conditions that create and feed storms. Here’s how scientists calculate storm probabilities, and why events like a 1,000-year storm can happen much more frequently in some places than that term suggests.

Forecasting the future based on the past

Estimates of rainfall return periods – how long it will be, on average, between storms of a given size – come from the U.S. National Oceanic and Atmospheric Administration, the home of the National Weather Service. NOAA publishes these projections in a series of reports called Atlas 14. Architects and engineers use them to design buildings, dams, bridges and other facilities to withstand heavy rainfall.

The estimates use past rainfall data to calculate how frequently rainstorms of various sizes occur at given locations. In places where historical rainfall observations have been collected for decades, it’s possible to calculate the amount of rain that is exceeded, on average, one or two times per year with very high confidence.

Experts then use statistical methods to estimate how frequently larger rain amounts would occur. As the amounts get bigger, the calculations become less precise. But it’s still possible to make reasonable estimates of very rare rain events.

The results are average probabilities that a certain amount of rain will fall in a given location in any given year. If a storm that produces 6 inches (15 centimeters) of rain within 24 hours has a 1% chance of occurring in any year, then we would expect such a storm to happen once in 100 years, so its return period is said to be 100 years. An event with a 0.1% chance of happening in any given year could be expected to occur once in 1,000 years on average, so it is referred to as a 1,000-year event.

It’s not ‘one and done’

The problem with terms like 100-year event or 1,000-year event is that many people hear them and assume they mean another storm of that size shouldn’t occur for another 99 or 999 years. That’s a reasonable conclusion, but it’s incorrect. Each storm is an individual event, so just because one becomes unusually large doesn’t mean that another storm a year later can’t exceed the odds as well.

Imagine you’re rolling a pair of dice. The odds of throwing a pair of sixes is small – just 1 in 36, or slightly less than 3%. But if you roll the dice again, the odds don’t change – they are the same for that roll as the one before.

A more accurate way to communicate storm odds is to think about the annual exceedance probability – the chance that a rainstorm of a given size could occur in any single year. A 1,000-year storm has a 0.1% chance of occurring in any year, and the same probability of occurring again the next year, and the year after.

Since the U.S. is a big country, we should expect to see a bunch of 0.1% probability rainstorms every year. The chance of such a storm occurring at any specific location is extremely low, but the chance of one occurring somewhere becomes quite a bit higher.

Put another way, even if you are unlikely to experience a 1,000-year storm at your location, there likely will be 1,000-year storms somewhere in the country every year.

Different areas see different kinds of storms

In the real world, actual rainstorms aren’t randomly distributed; they are a result of atmospheric processes like thunderstorms and hurricanes, which are produced by local and regional climate patterns. So a map of actual 1,000-year rainstorms would show clusters reflecting hurricanes along the East Coast, atmospheric rivers along the West Coast, and thunderstorm complexes in the Great Plains, where thunderstorm systems form.

Storm types matter because they have different durations. Almost all rare 1-hour extreme rainfall events are associated with thunderstorms, while those that last 48 or 72 hours often are caused by hurricanes or their remnants.

North Carolina and South Carolina, which are frequently affected by hurricanes and tropical storms, have seen numerous extreme rainfall events in recent years. They include record-setting rainstorms in October 2015 in South Carolina; Hurricane Matthew in 2016; Hurricane Florence in 2018; the aforementioned nameless storm in September 2024; and now, Hurricane Helene.

In fact, since 2002, the three U.S. storms that have dropped 1,000-year magnitude rainfall on the largest areas have all hit the Carolinas: the October 2015 storm, Florence and Helene.

Loading the weather dice

Why have so many storms that, historically and statistically, should be exceedingly rare, struck the Carolinas in just a few years? There are two main reasons, which are related.

“Cyclone,” Digital, Dream / Dreamland v3 / Clip2Comic, 2024

First, estimating the probability of rare events requires increasingly large amounts of data. NOAA’s Atlas 14 was last updated for the Carolinas in 2006, and those calculations only used data through 2000.

As more storms occur and more data is collected, the estimates get more robust. Given that reliable rainfall measurements only extend back about 100 years, the true probability of this much rain in the Carolinas may have been underestimated up until now.

Second, these statistics assume the climate isn’t changing, but we know that it is. Especially in regions near the coasts, the frequency of heavy rainfall has increased as a result of human-caused climate change. Warmer air can hold more moisture, and warmer oceans provide that moisture as the fuel for heavy rainfall.

As a result, climate change is making rainstorms that had been extremely rare now somewhat more likely. While the Carolinas may have been especially unlucky in recent years, the dice are also becoming loaded toward heavier rain – a trend that poses major challenges for emergency preparedness and recovery.

NOAA is currently developing Atlas 15, which will update current estimates with more recent data and will incorporate the effects of climate change. The agency also plans to modernize its estimates of a related quantity known as probable maximum precipitation, which is an estimate of the worst-case rainfall that could occur in a location.

Engineers use these estimates to design large critical facilities, such as dams, that can withstand the flood that would occur with the worst-case scenario rainfall at their sites. North Carolina has developed its own version of Atlas 15, due to the pressing need to plan transportation infrastructure to handle more events like Florence and Helene.

These updates will provide information that can be used for better planning and decision-making. Even so, extreme rainfall will still be a major hazard, with significant impacts on many U.S. communities.

Russ Schumacher, Professor of Atmospheric Science and Colorado State Climatologist, Colorado State University and Kathie Dello, Director, North Carolina State Climate Office, North Carolina State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

(The Conversation) – Millions of Americans have been watching with growing alarm as their homeowners insurance premiums rise and their coverage shrinks. Nationwide, premiums rose 34% between 2017 and 2023, and they continued to rise in 2024 across much of the country.

To add insult to injury, those rates go even higher if you make a claim – as much as 25% if you claim a total loss of your home.

Why is this happening?

There are a few reasons, but a common thread: Climate change is fueling more severe weather, and insurers are responding to rising damage claims. The losses are exacerbated by more frequent extreme weather disasters striking densely populated areas, rising construction costs and homeowners experiencing damage that was once more rare.

Parts of the U.S. have been seeing larger and more damaging hail, higher storm surges, massive and widespread wildfires, and heat waves that kink metal and buckle asphalt. In Houston, what used to be a 100-year disaster, such as Hurricane Harvey in 2017, is now a 1-in-23-years event, estimates by risk assessors at First Street Foundation suggest. In addition, more people are moving into coastal and wildland areas at risk from storms and wildfires.

Just a decade ago, few insurance companies had a comprehensive strategy for addressing climate risk as a core business issue. Today, insurance companies have no choice but to factor climate change into their policy models.

Rising damage costs, higher premiums

There’s a saying that to get someone to pay attention to climate change, put a price on it. Rising insurance costs are doing just that.

Increasing global temperatures lead to more extreme weather, and that means insurance companies have had to make higher payouts. In turn, they have been raising their prices and changing their coverage in order to remain solvent. That raises the costs for homeowners and for everyone else.

The importance of insurance to the economy cannot be understated. You generally cannot get a mortgage or even drive a car, build an office building or enter into contracts without insurance to protect against the inherent risks. Because insurance is so tightly woven into economies, state agencies review insurance companies’ proposals to increase premiums or reduce coverage.

The insurance companies are not making political statements with the increases. They are looking at the numbers, calculating risk and pricing it accordingly. And the numbers are concerning.

The arithmetic of climate risk

Insurance companies use data from past disasters and complex models to calculate expected future payouts. Then they price their policies to cover those expected costs. In doing so, they have to balance three concerns: keeping rates low enough to remain competitive, setting rates high enough to cover payouts and not running afoul of insurance regulators.

Photo by NASA on Unsplash

But climate change is disrupting those risk models. As global temperatures rise, driven by greenhouse gases from fossil fuel use and other human activities, past is no longer prologue: What happened over the past 10 to 20 years is less predictive of what will happen in the next 10 to 20 years.

The number of billion-dollar disasters in the U.S. each year offers a clear example. The average rose from 3.3 per year in the 1980s to 18.3 per year in the 10-year period ending in 2024, with all years adjusted for inflation.

With that more than fivefold increase in billion-dollar disasters came rising insurance costs in the Southeast because of hurricanes and extreme rainfall, in the West because of wildfires, and in the Midwest because of wind, hail and flood damage.

Hurricanes tend to be the most damaging single events. They caused more than US$692 billion in property damage in the U.S. between 2014 and 2023. But severe hail and windstorms, including tornadoes, are also costly; together, those on the billion-dollar disaster list did more than $246 billion in property damage over the same period.

As insurance companies adjust to the uncertainty, they may run a loss in one segment, such as homeowners insurance, but recoup their losses in other segments, such as auto or commercial insurance. But that cannot be sustained over the long term, and companies can be caught by unexpected events. California’s unprecedented wildfires in 2017 and 2018 wiped out nearly 25 years’ worth of profits for insurance companies in that state.

To balance their risk, insurance companies often turn to reinsurance companies; in effect, insurance companies that insure insurance companies. But reinsurers have also been raising their prices to cover their costs. Property reinsurance alone increased by 35% in 2023. Insurers are passing those costs to their policyholders.

What this means for your homeowners policy

Not only are homeowners insurance premiums going up, coverage is shrinking. In some cases, insurers are reducing or dropping coverage for items such as metal trim, doors and roof repair, increasing deductibles for risks such as hail and fire damage, or refusing to pay full replacement costs for things such as older roofs.

Some insurances companies are simply withdrawing from markets altogether, canceling existing policies or refusing to write new ones when risks become too uncertain or regulators do not approve their rate increases to cover costs. In recent years, State Farm and Allstate pulled back from California’s homeowner market, and Farmers, Progressive and AAA pulled back from the Florida market, which is seeing some of the highest insurance rates in the country.

State-run “insurers of last resort,” which can provide coverage for people who can’t get coverage from private companies, are struggling too. Taxpayers in states such as California and Florida have been forced to bail out their state insurers. And the National Flood Insurance Program has raised its premiums, leading 10 states to sue to stop them.

About 7.4% of U.S. homeowners have given up on insurance altogether, leaving an estimated $1.6 trillion in property value at risk, including in high-risk states such as Florida.

No, insurance costs aren’t done rising

According to NOAA data, 2023 was the hottest year on record “by far.” And 2024 could be even hotter. This general warming trend and the rise in extreme weather is expected to continue until greenhouse gas concentrations in the atmosphere are abated.

In the face of such worrying analyses, U.S. homeowners insurance will continue to get more expensive and cover less. And yet, Jacques de Vaucleroy, chairman of the board of reinsurance giant Swiss Re, believes U.S. insurance is still priced too low to fully cover the risk from climate change.

Climate change is a major factor in the rising cost of insurance. Join us for a special free webinar with experts Andrew Hoffman of the University of Michigan and Melanie Gall of Arizona State University to discuss the arithmetic behind these rising rates, what climate change has to do with it, and what may be coming in your future insurance bills.

Wednesday, October 9, 2024, 11:30 a.m. PT/2:30 p.m. ET.
Register for the webinar here.

Andrew J. Hoffman, Professor of Management & Organizations, Environment & Sustainability, and Sustainable Enterprise, University of Michigan

This article is republished from The Conversation under a Creative Commons license. Read the original article.

(The Conversation) – Hurricane Beryl was the latest Atlantic storm to rapidly intensify, growing quickly from a tropical storm into the strongest June hurricane on record in the Atlantic. It hit the Grenadine Islands with 150 mph winds and a destructive storm surge on July 1, 2024, then continued to intensify into the basin’s earliest Category 5 storm on record.

The damage Beryl caused, particularly on Carriacou and Petite Martinique, was extensive, Grenada Prime Minister Dickon Mitchell told a news briefing. “In half an hour, Carriacou was flattened.”

Beryl’s strength and rapid intensification were unusual for a storm so early in the season. This year, that is especially alarming as forecasters expect an exceptionally active Atlantic hurricane season.

Rapidly intensifying storms can put coastal communities in great danger and leave lasting scars. In 2022, for example, Hurricane Ian devastated portions of Florida after it rapidly intensified. To this day, residents are still recovering from the effects. As Beryl continued across the Caribbean Sea on July 2, Jamaica and the Cayman Islands were under hurricane warnings.

What causes hurricanes to rapidly intensify, and has climate change made rapid intensification more likely?

I research hurricanes, including how they form and what causes them to intensify, and am part of an initiative sponsored by the U.S. Office of Naval Research to better understand rapid intensification. I also work with scientists at the National Atmospheric and Oceanic Administration to analyze data collected by reconnaissance aircraft that fly into hurricanes. Here’s what we’re learning.

How did Hurricane Beryl intensify so quickly?

Rapid intensification occurs when a hurricane’s intensity increases by at least 35 mph over a 24-hour period. Beryl far exceeded that threshold, jumping from tropical storm strength, at 70 mph, to major hurricane strength, at 130 mph, in 24 hours.

A key ingredient for rapid intensification is warm water. The ocean temperature must be greater than 80 degrees Fahrenheit (27 Celsius) extending more than 150 feet below the surface. This reservoir of warm water provides the energy necessary to turbocharge a hurricane.

Scientists measure this reservoir of energy as ocean heat content. The ocean heat content leading up to Beryl was already extraordinarily high compared with past years. Normally, ocean heat content in the tropical Atlantic doesn’t reach such high levels until early September, which is when hurricane season typically peaks in activity.

Beryl is a storm more typical of the heart of hurricane season than of June, and its rapid intensification and strength have likely been driven by these unusually warm waters.

In addition to the high ocean heat content, research has shown other environmental factors need to typically align for rapid intensification to occur. These include:

• Low vertical wind shear, where the winds steering the hurricane do not change much in strength or direction over the depth of the storm. Strong wind shear makes it difficult for a storm to stay organized and maintain its strength.

• A moist atmosphere surrounding the storm, with heavy precipitation encircling the developing eye.

My research has shown that when this combination of factors is present, a hurricane can more efficiently take advantage of the energy it gathers from the ocean to power its winds, versus having to fight off drier, cooler air being injected from around the storm. The process is called ventilation.

Simultaneously, there is an increase in air being drawn inward toward the center, which quickly increases the strength of the vortex, similar to how a figure skater pulls their arms inward to gain spin. Rapid intensification is akin to a figure skater pulling in both their arms quickly and close to their body.

Has climate change affected the likelihood of rapid intensification?

As oceans warm and ocean heat content gets higher with climate change, it is reasonable to hypothesize that rapid intensification might be becoming more common. Evidence does suggest that rapid intensification of storms has become more common in the Atlantic.

Additionally, the peak intensification rates of hurricanes have increased by an average of 25% to 30% when comparing hurricane data between 1971–1990 and 2001–2020. That has resulted in more rapid intensification events like Beryl.

This increase in rapid intensification is due to those environmental factors – warm waters, low vertical wind shear and a moist atmosphere – aligning more frequently and giving hurricanes more opportunity to rapidly intensify.

The good news for anyone living in a region prone to hurricanes is that hurricane prediction models are getting better at forecasting rapid intensification in advance, so they can give residents and emergency managers more of a heads-up on potential threats. NOAA’s newest hurricane model, the Hurricane Analysis and Forecast System, shows promise to further improve hurricane forecasts, and artificial intelligence could provide more tools to predict rapid intensification.

This article has been updated with Cayman Islands hurricane watch upgraded to a hurricane warning.

Brian Tang, Associate Professor of Atmospheric Science, University at Albany, State University of New York

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Feature Image: Hurricane Beryl hit the island of Carriacou, Grenada, on July 1, 2024, with 150 mph sustained winds: NOAA .

I mean, don’t you think we humans are kinda mad? And worse yet, at some deep level, we simply can’t seem to stop. All too often, we just can’t curb our urge to destroy.

Looking back, the desire to make war and obliterate our “enemies” is a deeply ingrained and repetitive pattern in our history. Each individual example can, of course, be explained (away) in its own fashion, but the overall pattern? Hmmm…

I mean, you can certainly “understand” the Russian invasion of Ukraine. Depending on your politics, you can explain it in terms of the threatening expansion of NATO or of a country run by an autocrat willing to see countless numbers of his people die (no, I’m not even thinking about the tens of thousands of dead Ukrainians) in order to take more territory — whether in parts of Georgia (no, not that Georgia!), Ukraine, or god knows where else — and make himself ever more impressively (or do I mean depressively?) imperial. Phew! That was a long one, but explanations about war-making tend to be that way.

And yes, if you want, you also can undoubtedly explain the ongoing nightmare in Gaza, beginning with Hamas’s horrific October 7th attack on Israel and followed by the outrageous urge of Prime Minister Benjamin Netanyahu and his disturbingly right-wing compatriots to slaughter the population of that strip of land right down to the smallest child. In some grim fashion, given our history, such acts seem all too sadly human.

You could also undoubtedly offer explanations for the endless — yes, that’s a reasonable word to use here! — not to speak of disastrous wars my own country has stomped into since World War II ended, first as the leader of the “free world” and then as the leader of who knows what. Those conflicts ranged from Korea in the 1950s and Vietnam, Laos, and Cambodia in the 1960s and 1970s to Afghanistan and Iraq, among other places, in this century. And undoubtedly it’s even possible to explain (away) the nightmarish civil war still devastating Sudan that’s already displaced more than eight million people without being noticed by much of the rest of the world.

Something New in the Planetary Bloodstream

In a sense, war is human history. It’s been the rare moment when we’ve proven capable of not making war on ourselves somewhere on this planet. It seems to be in the bloodstream, so to speak (as in the endless streams, even rivers, of blood eternally being spilled). And in a sense, war, the urge to take someone else’s territory or simply kill endless numbers of… well, us… has certainly been in that very same bloodstream at least since the first great literary work of the Western world, The Iliad, was written. In some sense, you could say that, 3,000 years later, we’re all still in Troy.

Oh, wait, that’s both true and not, because there is indeed something new in the planetary bloodstream. And I’m not even thinking about our endless ability to find ever “better” and more devastating ways to kill one another — from the spear to the AR-15 semi-automatic rifle (reputedly now owned by one of every 20 Americans), the bow and arrow to the AI-driven drone, the hand grenade to atomic weaponry. (And don’t forget that Vladimir Putin is already threatening to use “tactical” nuclear weapons in Ukraine — never mind that some of them are significantly more powerful than the bombs that, in August 1945, obliterated the Japanese cities of Hiroshima and Nagasaki.)

No, what I have in mind is that other way we humans have found to potentially devastate our world: the burning of fossil fuels. Yes, it started with the massive consumption of coal during the early stages of the Industrial Revolution in the eighteenth and nineteenth centuries, and it’s simply never ended. (China, in fact, now uses more coal than the rest of the world combined and continues to build coal power plants.) By now, with oil and natural gas added to the mix in staggering quantities, records are being set monthly as ever greater heat waves, increasingly violent storms, startling flooding, and devastating fires are becoming part of our everyday lives. Typical was Miami’s May heat index that recently hit an unheard-of 112 degrees Fahrenheit, 11 degrees higher than at any past date in May ever. That should hardly shock us, however, since, as that superb environmentalist Bill McKibben reports, “A new study out today shows that heat waves have tripled since the 1960s in this country, and that deaths from those hot spells are up 800%.” And, of course, far worse is predicted for the decades to come, as those burning fossil fuels continue to pour greenhouse gases into the atmosphere at record rates.

Buy the Book

Forget what we officially call wars (anything but easy to do these days if you happen to be Gazan, Sudanese, or Ukrainian) and consider this the increasingly devastating new way we have of warring on ourselves and our planet. While there’s still a lot to learn about global warming, also known as climate change (terms far too mild for what’s actually happening), we already know far too much not to consider it the ultimate danger — other than nuclear war, of course. In fact, the difference between nuclear war and global warming could be that, since August 1945 (except for nuclear tests), such weaponry has never been used again, while the distinctly apocalyptic “weaponry” of climate change is still ratcheting up in a staggering fashion.

Image by Patou Ricard from Pixabay

A War Against the World as We’ve Known It

Climate change is certainly something Americans should know about. After all, only the other week, Donald (“drill, baby, drill“) Trump sat down with a group of fossil-fuel CEOs and reportedly suggested that, for a billion dollars in campaign financing, a bribe of the first order, he would toss out all of Joe Biden’s attempts to rein in the oil, natural gas, and coal industries and encourage them instead to make further fortunes by turning this planet into a cinder. (In truth, that wasn’t really much of an offer, since he had already made it clear that he was planning to do just that anyway, starting on “day one” of his next term in office.)

Of course, who needs Donald Trump when, as the New York Times reported recently, despite President Biden’s distinct attempts to limit the use of fossil fuels during his tenure in the White House, “oil and gas production have set records under the Biden administration and the United States is the world’s leading exporter of liquefied natural gas. Even with the [administration’s] pause on permits for new [natural gas] export terminals, the United States is still on track to nearly double its export capacity by 2027 because of projects already permitted and under construction.” And mind you, we’re talking about the country that, according to the U.S. Energy Information Administration, “produced more crude oil than any nation at any time… for the past six years in a row,” reaching — yes, indeed! — a new record in 2023.

And despite all of what I’ve just described, consider it an irony that the only true world war of the moment (think of it, in fact, as a slow-motion World War III) doesn’t normally get enough headlines (though there are, of course, exceptions) or the attention in the mainstream media that the wars in Gaza and Ukraine so regularly have. No matter that last year was the hottest in human history and that each of the last 11 months was the warmest of its kind on record. Still, if you want to follow what’s functionally our only true world war in the mainstream world, there’s one obvious place to go, the British Guardian, which regularly highlights reporting on the subject and even has an online “climate-crisis” section.

Here, for instance, are just a few of the things you could have learned from that paper’s reporting in the last month or so and tell me they shouldn’t have been headline news everywhere. Take the Guardian‘s Oliver Milman recently writing that “the largest ever recorded leap in the amount of carbon dioxide laden in the world’s atmosphere has just occurred… The global average concentration of carbon dioxide in March this year was 4.7 parts per million (or ppm) higher than it was in March last year, which is a record-breaking increase in CO₂ levels over a 12-month period.” Or the staggering heat waves that struck across Asia this spring “causing deaths, water shortages, crop losses and widespread school closures,” as Damian Carrington, that paper’s environment editor, reported. And mind you, such searing temperatures were “made 45 times more likely in India” by the climate crisis.

Do you even remember when not passing 1.5 degrees Centigrade was the goal of the countries that put together the 2015 Paris climate accord? Well, if you don’t, no problem, since, as Carrington also recently reported, thanks to an exclusive Guardian survey, “Hundreds of the world’s leading climate scientists expect global temperatures to rise to at least 2.5C (4.5F) above preindustrial levels this century, blasting past internationally agreed targets and causing catastrophic consequences for humanity and the planet.” And almost half of them expect it to hit 3C! Now, try to imagine that future planet of, well, I’m not sure you can say “ours” anymore, or better yet, check out another recent Carrington piece on the kinds of horrors — and they would be horrors of an unprecedented sort — such scientists now think a 3C world might hold for us.

Oh, and as Milman wrote recently, a new report suggests that “the economic damage wrought by climate change is six times worse than previously thought.” That’s already! And we’ve also already crept close to that 1.5C mark. But let me not go on. You get the idea. And each of those stories should have been a blazing headline across a planet that’s already feeling the heat in every sense imaginable, even if, in our normal reckoning, what’s happening doesn’t yet count as a world war (or at least a war on the world as we’ve known it).

Don’t you find all of that breathtaking (given the nature of heat)? And isn’t it amazing that, despite what it means for our future, it’s so often hardly considered headline-making news?

And mind you, there’s so much we don’t yet even know: Is the fierce tornado season that’s recently stretched from Texas through Iowa and beyond another climate-change-induced phenomenon? It’s certainly possible. Will the coming hurricane season set a series of records from hell, as the National Oceanic and Atmospheric Administration (NOAA) is now warning us, thanks in part to the fact that the tropical waters of the Atlantic Ocean have heated to all-time-record levels? Again, we’ll have to wait (but not for long) to see what happens. And is that record rise in U.S. billion-dollar — yes, billion-dollar! — weather disasters recorded by NOAA in 2023, another climate-change-induced horror? It certainly seems likely.

We are, in other words, already in a mad new world of “war” (as well as the mad old version of the same). And given how possible it is that Donald Trump will become President Fossil Fuel again, we may be left to face an all too literally mad future (along with staggering new profits for the big fossil-fuel companies) in what, until recently, still passed, despite endless disastrous wars, for the greatest power on the face of the Earth. And in retrospect, in climate terms, I suspect that even Joe Biden will seem distinctly lacking and congressional Republicans mad beyond words.

Take, for instance, President Biden’s actions in relation to this planet’s other greenhouse-gas burning monster, China. (While the U.S. has historically been the greatest greenhouse gas emitter, China now tops the list.) Unlike Donald Trump, Joe Biden does indeed take climate change seriously, but he’s also supported Israel in a war from hell that’s throwing vast amounts of greenhouse gases into the atmosphere and, when it comes to China, his urge hasn’t truly been to cooperate. Instead, his focus has been on expanding the U.S. military presence throughout Asia, including putting Green Berets on an island just 10 kilometers off China’s coast. (Imagine how this country would react if — and it would hardly be comparable — China were to assign its version of special forces troops to Cuba!)  In other words, he’s been at work creating the conditions for a new, if not hot, then certainly all-too-warm war between the two greatest greenhouse-gas polluters on this ever-warming planet. 

Brilliant! And the Chinese response? To pal it up with Vladimir Putin! (Equally brilliant!)

As mid-2024 approaches, the question remains: Can we humans stop making war on each other or preparing for yet more of the same and begin dealing with a planet heading to hell in a proverbial handbasket? Can we face the fact that the enemy is indeed us?

Copyright 2024 Tom Engelhardt

Via Tomdispatch.com