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.

—–

Bonus Video:

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

Three-quarters of Earth’s land has become drier since 1990.

Droughts come and go – more often and more extreme with the incessant rise of greenhouse gas emissions over the last three decades – but burning fossil fuels is transforming our blue planet. A new report from scientists convened by the United Nations found that an area as large as India has become arid, and it’s probably permanent.

A transition from humid to dry land is underway that has shrunk the area available to grow food, costing Africa 12% of its GDP and depleting our natural buffer to rising temperatures. We have covered several consequences of humanity’s fossil fuel addiction in this newsletter. Today we turn to the loss of life-giving moisture – what is driving it, and what we are ultimately losing.

Why is the land drying out so fast? It’s partly because there is more heat trapped in the atmosphere by greenhouse gases emitted from burning fossil fuels. This excess heat has exacerbated evaporation and is drawing more moisture out of soil.

‘Oil, not soil’

Climate change has also made the weather more volatile. When drought does cede to rain, more of it arrives in bruising downpours that slough the topsoil.

A stable climate would deliver a year’s rain more evenly and gently, nourishing the soil so that it can nurture microbes that hold onto water and release nutrients.

This is the kind of soil that industrial civilisation inherited. It’s disappearing.

“Soil is being lost up to 100 times faster than it is formed, and desertification is growing year on year,” says Anna Krzywoszynska, a sustainable food expert at the University of Sheffield.

“The truth is, the modern farming system is based around oil, not soil.”

Fossil fuels have unleashed agriculture from the constraints of local ecology. Once, the nutrients that were taken from the soil in the form of food had to be replaced using organic waste, Krzywoszynska says. Synthetic nitrogen fertilisers, made with fossil energy at great cost to the climate, changed all that.

Next came diesel-powered machinery that brought more wilderness into cultivation. Farm vehicles as heavy as the biggest dinosaurs now churn and compact the soil, making it difficult for earthworms and assorted soil organisms to maintain it.

Tractors and chemicals served humanity for a long time, Krzywoszynska says. But soil is now so degraded that no amount of fossil help can compensate.

“Across the world, soils have been pushed beyond their capacity to recover, and humanity’s ability to feed itself is now in danger.”

Green pumps and white mirrors

The primary way that we have been making up for lost food yield is turning more forests into farms. This is accelerating our journey towards a drier, less liveable world because forests, if allowed to thrive, create their own rain.

“Water sucked up by tree roots is pumped back into the atmosphere where it forms clouds which eventually release the water as rain to be reabsorbed by trees,” say Callum Smith, Dominick Spracklen and Jess Baker, a team of biologists at the University of Leeds who study the Amazon rainforest.

“In the Amazon and Congo river basins, somewhere between a quarter and a half of all rainfall comes from moisture pumped from the forest itself.”

Image by MAMADOU TRAORE from Pixabay

Some experts have argued that the UN report understates Earth’s growing aridity by overlooking the water that is held in snow caps, ice sheets and glaciers. Climate change is melting this frozen reservoir, which also serves as a seasonal source of water.

“And as water in its bright-white solid form is much more effective at reflecting heat from the sun, its rapid loss is also accelerating global heating,” says Mark Brandon, a professor of polar oceanography at The Open University.

How do we adapt our relationship with the land to remoisturise the world? Krzywoszynska argues that there is no easy solution, but the future of food-growing “is localised and diverse”.

“To ensure that we eat well and live well in the future, we’ll need to reverse the trend towards greater homogenisation which drove food systems so far.”

The good news, according to Krzywoszynska, is that farmers are experimenting with methods that restore the soil even as they produce a diverse range of nutritious food. These innovators need rights and secure access to the land, the opportunity to share their experiences and financial and political support.

“Regenerating land is a win-win, for humans and their ecosystems, if we dare to look beyond the immediate short-term horizon,” she says.

Jack Marley, Environment + Energy Editor, The Conversation

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

Heat and drought would rank high on this list. The Middle East is heating twice as fast as the global average. Egypt and Iraq are especially vulnerable to sea level rise. Some of the consequent threats can only be dealt with by inter-governmental cooperation. But that kind of cooperation is hard to come by as things now stand.

An example of a cross-border problem is the substantial reliance of numerous MENA nations on imported food, especially grains, which renders them vulnerable to global food price fluctuations caused by climate-related events (or wars) in other regions.

We saw this problem in the Russia-Ukraine War, which threatened Middle East wheat supplies. But climate-drive mega-droughts could have similar implications.

MENA countries are not well positioned to deal with climate change impacts, they point out, given that governments tend to be highly centralized, with power concentrated in the hands of oligarchs or juntas dependent directly or indirectly on oil and gas. The oligarchs are out for themselves, seeking “rents” from oil-rich countries where they don’t have such mineral wealth themselves. They exclude from decision-making grass-roots organizations, workers, the poor and women, who are often on the front lines of global heating and know better than the air-conditioned, petroleum-swigging elites how dangerous it is. All this is true for individual countries. Imagine getting them to cooperate on climate resilience or the green energy transition across borders.

The oligarchs of the region promote water-intensive crops like citrus fruits for export even in arid countries, because they can make money on the exports, and even though their countries have to import a lot of food. That is, they could put in staples like grain instead of citrus fruits, but then they wouldn’t make money from exports. Their people would, however, be less hungry.

For another example, they say, the elites in Tunisia concentrate on olive cultivation for the world market (it is the third largest producer). But there are so many olive orchards and so few of any other sort of crop that the country is making difficulties for itself. Monocultures are especially vulnerable to disease outbreaks or global price fluctuations. The olive orchards drink up the country’s agricultural water, making it hard for farmers to put in other crops.

Embed from Getty Images
An irrigation system is used in an olive grove located in Siliana, Tunisia, on May 10, 2024. Farmers face a major problem in keeping their fields productive due to water stress and drought. (Photo by Chedly Ben Ibrahim/NurPhoto via Getty Images)

In Libya, the army controls much of the economy. The country is heavily dependent on oil exports, and suffers when petroleum prices plummet. The country imports 75% of its food, so if anything disrupts the global food supply chain, Libyans are in big trouble. Petroleum is mostly used to fuel vehicles, but as the world electrifies and goes to EVs, Libyans will be up the creek if they don’t find another source of wealth.

There are five big categories of cross-country threats, they say:

1.The Biophysical: “risks for trans-boundary ecosystems, such as international river basins, oceans and the atmosphere.” They give the example of Turkey’s dam-building at the headwaters of the Euphrates, which is threatening water flows in Iraq, which depends on two large rivers for survival. Climate change is also reducing flow. Iraq could be in big trouble over this trans-boundary problem.

2. Financial. Foreign direct investment in the region could fall substantially because of climate impacts, hampering infrastructure projects. Lack of infrastructural adaptation could hurt efforts to come to terms with climate change.

3. Trade: “Potential risks to international trade, such as the import and export of climate-sensitive crops and implications for food security.” MENA imports 50% of its food from the outside, and if there are droughts elsewhere in the world things could turn very dangerous.

4. People-Centered: They point to the millions of displaced people in the region. Half of Syrians had to move house during the Civil War, in which a major drought was probably implicated. Some 11 million Sudanese have been displaced by the current civil war, in a population of 48 million. They don’t say so, but the Nile Delta in Egypt is very populous (60 million people) and very low-lying, at risk from the rising waters of the Mediterranean. God knows where they will go.

5. Geopolitical. This term refers to regional conflict. We see this (this is me, not the report) in Lebanon, where Israel’s attacks have displaced 1.2 million people. There are only about 4.5 million Lebanese.

While Europe has spent hundreds of millions of dollars in aid to help MENA countries begin the transition to solar and wind energy, it has offered very little money to help Middle Eastern countries become more resilient in the face of climate change.

The authors note that the Middle East and North Africa is a diverse geographical area. It has its famous deserts but also mountain ranges, green valleys like Lebanon’s Biqa’ (now being bombed by Israel), long river valleys, mangrove stands along the seas, and swamps in southern Iraq.

The way contemporary analysts categorize the Middle East, it stretches from Iran in the east to Morocco in the far west, and from Syria in the north to Yemen in the south. Nearly 500 million people inhabit the area, and many states within it still have high birth rates, giving it millions of youths. The median age is something like 22 or 24, compared to 38.5 for the United States. Like India and Africa, it is young.

Some parts of the region are desperately poor, others are fabulously wealthy. Outside the petroleum states, they point out, parts of Syria, Iraq, Yemen, the Occupied Palestinian Territories, and Libya, are low-income, conflict-impacted societies facing severe challenges like human displacement and acute poverty. Simultaneously, middle-income nations like Morocco and Egypt are proactively exploring business opportunities within the global green transition.

Morocco and Turkey are virtually the only countries in the area that have had some success transitioning their grids to sustainable sources of energy, though much poorer Morocco is more advanced in wind and solar, while Turkey depends more heavily on hydroelectricity.

(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.

—–

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.

( Foreign Policy in Focus ) – Azerbaijan is making the most of its hosting of the UN climate summit (COP29) in November this year. Its president, Ilham Aliyev, has been on a whirlwind tour of the world to court major nations for a climate finance pact that will feature Baku’s initiative on a New Collective Quantified Goal (NCQG), which originally was a pledge to provide $100 billion annually for climate action in developing countries. He also enlisted the support of his neighbor, Russia.

On August 18-19, Russian President Vladimir Putin made a two-day state visit to Azerbaijan. Aliyev invited him to attend COP29. Putin hasn’t been fond of climate summits, but this one will be hard for him to skip. If he attends, he will, for the first time since the invasion of Ukraine, sit next to leaders of P5, G-7, BRICS (Brazil, Russia, India, China, and South Africa), G-20, and the 38-member OECD (Organization of Economic Cooperation and Development) countries. Except for G-7, Russia is a key member of all these groupings.

Putin will be tempted to support the NCQG, since it would give him an opportunity to name and shame those who have been historically the world’s largest emitters of greenhouse gases (GHG). But there is an irony involved here. The Russian economy is awash in resource extraction, especially the extraction of oil and natural gas. Russia is world’s fourth largest emitter of greenhouse gasses, after China, the United States, and India. Should Russia call out rich nations for their historical contribution to GHG emissions, it will be the pot calling the kettle black.

Besides their shared past as former Soviet republics, Azerbaijan and Russia are fellow littoral states that share the long, transnational Caspian coastline. With a surface area of 143,000 square miles, the Caspian is the world’s largest inland body of water. It is “inland” because it doesn’t feed into any larger waterway, such as the ocean. Its year-round cumulative moisture makes coastal economies hum.

As one of the five littoral states—the others being Kazakhstan, Russia, Iran, and Turkmenistan—Azerbaijan is the most dependent upon the Caspian. One-fourth of Baku’s oil reserves are located offshore in the Caspian. Azerbaijan could live without this oil, but it cannot live without the food, water, and ecological treasures that the Caspian lavishes upon it. Sturgeon is the queen fish of the Caspian, which yields the world delicacy of caviar. Up to 90 percent of the world’s caviar is sourced from the Caspian. Baku, the capital city of Azerbaijan and host to COP29, is built on the shore of the Caspian. The lake is the city’s water tower and its food pantry.

But the Caspian is fast drying up. With climate-induced soaring temperatures, the lake is rapidly evaporating, leaving behind sprawling patches of dry land. On average, the Caspian has been receding by 20 centimeters per year. It is projected to drop by 18 meters by the end of the century, while the northern Caspian is already only 5-6 meters deep. It has now passed below the level at which it can support the marine ecosystem.

Aliyev showed Putin rocks that were peeking out of the lake’s fast developing shallows. The Azeri leader fears that this process will eventually turn the lake into an island, just as it did to the Aral Sea. The latter’s seabed is now land surface with miles upon miles of dirt trails. The Kazakh port city of Aqtau has already dried up, leaving the vibrant urban center and its economy in ruin.

Photo by MohammadReza Jelveh on Unsplash

At slightly over a million square miles, Kazakhstan is comparable in size to Western Europe and thus can absorb the loss of a city. Azerbaijan is, however, far more compact with a land area of just 33,436 square miles. Its surface and subsurface territorial waters in the Caspian are twice as large as its landmass. Losing so much of the country to climate change would be unthinkable for any Azeri.

Putin has promised Aliyev to save the lake. Despite his promise, there is little Putin can do. Putin’s Russia is an upstream country on the Caspian. The other four coastal nations, including Azerbaijan, want Moscow to cease impounding and diverting tributaries to the Caspian. One such tributary is the Volga River, which is the longest and the largest (in volume) body of water on the European continent. The Volga’s headwaters are located northwest of Moscow. Caspian nations argue that the Volga makes up 80 percent of the inflow to the lake. The remainder (20 per cent) comes from two downstream river systems: the Kurra and the Aras. The Volga’s uninterrupted flow is, therefore, critical to the life of the Caspian.

But Russia has built 40 dams and diversions on the Volga, and 18 more are in various stages of development, all of which have slashed flow to the Caspian to a trickle. Dams and diversions do diminish inflows, but climate change too is having an impact. If the Caspian itself is evaporating from hotter and drier conditions, the Volga is no exception to this phenomenon either. Reduced precipitation is contributing to the problem. A case in point is the transboundary Helmand River that drains both Afghanistan and Iran. Lack of rainfall has reduced the Helmand’s flow so much that it seldom makes it to Iran, inflaming tensions between Kabul and Tehran.

Ironically, all five Caspian economies – Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan — are heavily dependent on fossil fuel production, which is at the heart of climate breakdown. Despite platitudes about reaching net zero, the global capitalist economy is also hooked on fossil fuels.  As a result, carbon emissions are on the rise, and atmospheric temperatures are smashing records. Since the Paris Climate Pact in 2015, the world has gone backward on climate change.

Unless hydrocarbon resources are kept in the ground, there is little hope of saving world monuments such as the Caspian. COP 29 is a great occasion to showcase what the Caspian means to the region and the rest of the world. Azerbaijan’s initiative on climate finance couldn’t be more urgent to help preserve the Caspian and similar natural wonders. The United States will better serve the cause of climate stability by taking the lead in supporting the NCQG. President Joe Biden could further burnish his climate legacy by giving his vision at COP 29 of the “Great Transition” to a global green economy. Biden and others need to go well beyond the business as usual of climate adaptation to strike at the root of the problem: fossil capitalism.