(The Conversation) – Many experts believe we may soon face a mass extinction event, with a high proportion of Earth’s species dying out. Projections indicate the climate will continue to change for centuries to come, and this is a significant threat to biodiversity that has already had an impact on many species.

Despite the threat that climate change poses to biodiversity, we do not yet fully understand how it causes animals to go extinct. In our new paper, published in Science, we used the fossil record to make more precise estimates.

The geological rock record provides critical insight on past extinctions caused by a variety of climate change events. Fossils therefore offer a rare opportunity to understand the mechanisms of extinction and investigate how climate shifts have led to extinction in the past. Understanding why species went extinct under natural, pre-human conditions is paramount, since human-induced extinction drivers are accumulating over time.

By identifying which traits are linked to extinction, we can potentially use this knowledge to identify at-risk species to prioritise in conservation efforts.

In our latest research article, we analysed a data set comprising over 290,000 marine invertebrate fossils, covering the last 485 million years of Earth’s history. We looked directly for the traits most crucial for survival in the geologic past.

Previous studies have highlighted small body size and limited geographic range size (the spatial extent occupied by a species) as key predictors of extinction risk throughout geological history.

We reconstructed the climate for 81 geological stages across the Phanerozoic (the current geological era, starting 541 million years ago). And we used climate models to determine the range of temperatures that each species can endure.

Image by Robert Balog from Pixabay

These factors were then compared against geographic range size and body size to assess their relative importance. We then estimated an external factor that may impact risk of extinction: the magnitude of climate change experienced by each species.

We assessed how the intrinsic traits, such as temperature tolerance and body size, compared to climate change in affecting a species’ risk of extinction. Our study is the first to directly compare traits to external factors in determining what drives extinction.

Our findings revealed that species inhabiting climatic extremes, such as polar or equatorial regions, were particularly susceptible to extinction. Species with a narrow thermal tolerance of approximately less than 15°C faced a significantly higher risk of extinction. We also found that smaller-bodied species are more prone to extinction due to both climatic and other changes.

However, the most important predictor of extinction risk was geographic range size. Species with smaller ranges, occupying more geographically-confined areas, had a higher likelihood of extinction.

Conservation is needed

Alarmingly, our research has, for the first time, identified climate change as a significant predictor of extinction, alongside other species’ traits.

We observed that species subjected to local climate changes of 7°C or greater across geological stages were significantly more likely to face extinction. This suggests that surpassing this climate change threshold increases the likelihood of extinction for a species, regardless of its other traits.

That said, the research shows that there is a cumulative effect of these variables on extinction risk. This underscores the importance of considering a broad spectrum of factors when assessing vulnerability to extinction.

For instance, a species residing in polar regions, characterised by a small geographic range size and body size, and subjected to significant climate change, would face a higher extinction risk than what might be inferred if considering only its geographic range. This holistic approach reveals the interplay between various biological and environmental factors in determining species’ survival over geological timescales.

Our research underscores the urgent challenge climate change poses to global biodiversity. But it also emphasises the necessity for continued research.

Many uncertainties remain when it comes to extinction risk, particularly around why certain traits confer extinction resistance and how traits interact to effect extinction risk. This additional research is essential to fully leverage our study’s implications for conservation strategies.

Without immediate and targeted conservation efforts, informed by a deeper understanding, we risk moving toward a sixth mass extinction event. So our work provides a pivotal call to action. We should mitigate climate change, but also do more research to bolster our understanding of the impacts on vulnerable species.

Erin Saupe, Associate Professor, Palaeobiology, University of Oxford and Cooper Malanoski, PhD Candidate in Geology, University of Oxford

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

National weather analysts released their 2023 billion-dollar disasters list on Jan. 9, just as 2024 was getting off to a ferocious start. A blizzard was sweeping across across the Plains and Midwest, and the South and East faced flood risks from extreme downpours.

The U.S. set an unwelcome record for weather and climate disasters in 2023, with 28 disasters that exceeded more than US$1 billion in damage each.

While it wasn’t the most expensive year overall – the costliest years included multiple hurricane strikes – it had the highest number of billion-dollar storms, floods, droughts and fires of any year since counting began in 1980, with six more than any other year, accounting for inflation.

The year’s most expensive disaster started with an unprecedented heat wave that sat over Texas for weeks over the summer and then spread into the South and Midwest, helping fuel a destructive drought. The extreme heat and lack of rain dried up fields, forced ranchers to sell off livestock and restricted commerce on the Mississippi River, causing about US$14.5 billion in damage, according to the National Oceanic and Atmospheric Administration’s conservative estimates.

Extreme dryness in Hawaii contributed to another multi-billion-dollar disaster as it fueled devastating wildfires that destroyed Lahaina, Hawaii, in August.

Other billion-dollar disasters included Hurricane Idalia, which hit Florida in August; floods in the Northeast and California; and nearly two dozen other severe storms across the country. States in a swath from Texas to Ohio were hit by multiple billion-dollar storms.

NBC News: “New details of the devastating Lahaina wildfire that killed over 100 people”

El Niño played a role in some of these disasters, but at the root of the world’s increasingly frequent extreme heat and weather is global warming. The year 2023 was the hottest on record globally and the fifth warmest in the U.S.

I am an atmospheric scientist who studies the changing climate. Here’s a quick look at what global warming has to do with wildfires, storms and other weather and climate disasters.

Dangerous heat waves and devastating wildfires

When greenhouse gases, such as carbon dioxide from vehicles and power plants, accumulate in the atmosphere, they act like a thermal blanket that warms the planet.

These gases let in high-energy solar radiation while absorbing outgoing low-energy radiation in the form of heat from the Earth. The energy imbalance at the Earth’s surface gradually increases the surface temperature of the land and oceans.

The most direct consequence of this warming is more days with abnormally high temperatures, as large parts of the country saw in 2023.

Phoenix went 30 days with daily high temperatures at 110 F (43.3 C) or higher and recorded its highest minimum nighttime temperature, with temperatures on July 19 never falling below 97 F (36.1 C).

Although heat waves result from weather fluctuations, global warming has raised the baseline, making heat waves more frequent, more intense and longer-lasting.

That heat also fuels wildfires.

Increased evaporation removes more moisture from the ground, drying out soil, grasses and other organic material, which creates favorable conditions for wildfires. All it takes is a lightning strike or spark from a power line to start a blaze.

How global warming fuels extreme storms

As more heat is stored as energy in the atmosphere and oceans, it doesn’t just increase the temperature – it can also increase the amount of water vapor in the atmosphere.

When that water vapor condenses to liquid and falls as rain, it releases a large amount of energy. This is called latent heat, and it is the main fuel for all storm systems. When temperatures are higher and the atmosphere has more moisture, that additional energy can fuel stronger, longer-lasting storms.

Tropical storms are similarly fueled by latent heat coming from warm ocean water. That is why they only form when the sea surface temperature reaches a critical level of around 80 F (27 C).

With 90% of the excess heat from global warming being absorbed by the ocean, there has been a significant increase in the global sea surface temperature, including record-breaking levels in 2023.

Higher sea surface temperatures can lead to stronger hurricanes, longer hurricane seasons and the faster intensification of tropical storms.

Cold snaps have global warming connections, too

It might seem counterintuitive, but global warming can also contribute to cold snaps in the U.S. That’s because it alters the general circulation of Earth’s atmosphere.

The Earth’s atmosphere is constantly moving in large-scale circulation patterns in the forms of near-surface wind belts, such as the trade winds, and upper-level jet streams. These patterns are caused by the temperature difference between the polar and equatorial regions.

As the Earth warms, the polar regions are heating up more than twice as fast as the equator. This can shift weather patterns, leading to extreme events in unexpected places. Anyone who has experienced a “polar vortex event” knows how it feels when the jet stream dips southward, bringing frigid Arctic air and winter storms, despite the generally warmer winters.

In sum, a warmer world is a more violent world, with the additional heat fueling increasingly more extreme weather events.

This article, originally published Dec. 19, 2023, was updated Jan. 9, 2024, with NOAA’s disasters list.

Shuang-Ye Wu, Professor of Geology and Environmental Geosciences, University of Dayton

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

The health benefits of eating seafood are appreciated in many cultures which rely upon it to provide critical nutrients vital to our physical and mental development and health. Eating fish and shellfish provides significant benefits to neurological development and functioning and provides protection against the risks of coronary heart disease and Type 2 diabetes.

Over three billion people get at least 20 per cent of their daily animal protein from fish. In countries from Bangladesh to Cambodia, Gambia, Ghana, Indonesia, Sierra Leone and Sri Lanka, fish consumption accounts for 50 per cent or more of daily intake.

However, expansive growth of human populations globally puts immense pressure on the health of wild fish stocks. Fish catches peaked in 1996, and one-third are considered overexploited. With less fish available to still more people, the future of fish as an accessible source of nutritious food is at risk, particularly among low-income countries.

Seafood nutrient losses

Threats to seafood access aren’t just due to overharvesting. There is a growing body of research showing that higher water temperatures due to climate change can impact the presence and abundance of the catch, through shifts in species distribution and changes in the species caught. This impacts the amount that can be harvested, as well as the nutritional value of that harvest.

A new study (which Aaron MacNeil contributed to) quantified nutrient availability from seafood through time considering the twin impacts of overfishing and climate change.

Focusing on four key nutrients important to human health — calcium, iron, omega-3 fatty acids and protein — the authors argue that nutrient availability in seafood has been declining since 1990 and will further decline by around 30 per cent by 2100 in predominately tropical, low-income countries with 4 C of warming.

These predicted losses are significant. While global famines are now relatively rare, some 50 million people suffer from “hidden hunger” — nutrient-deficient diets that are masked by being otherwise calorie-sufficient.

For animal-derived nutrients such as B12 and omega-3 fatty acids, nearly 20 per cent of the global population are at risk of becoming nutrient-deficient in coming decades due to reliance on wild-caught fish.

Climate change is also affecting natural cycles of nutrients in the ocean. For example, it has been predicted that increasing water temperatures will cause a decline in natural omega-3 availability from seafood by more than 50 per cent by 2100. At the bottom of the food chain, microalgae that naturally produce omega-3s are less productive at warmer temperatures and this cascades through marine and freshwater food chains resulting in fish having less omega-3s available to eat and store in their bodies.

These kinds of climate-caused losses are expected to disproportionately affect vulnerable populations, especially in inland Africa.

Challenges and strategies for nutritious seafood

Aquaculture can help supply some of these missing nutrients, but it is an industry also vulnerable to the effects of climate change. A recent study predicted that 90 per cent of aquaculture will be impacted by climate change, where warm waters increase disease outbreaks, harmful algal blooms and impact the availability of feed supplies.

Global disparities already exist in food security that will be exacerbated by climate change in the future. Yet the effects of warming waters on nutrient availability from seafood will compound these inequities among tropical and low-income countries.

These results suggest a major challenge to our future nutritional security that demands strong fisheries and aquaculture management to facilitate equitable distribution of nutritious seafoods.

Improvements are possible.

For example, redirecting nine per cent of Namibia’s fisheries toward its coastal population would alleviate the severe iron deficiencies experienced there. Policies that prioritize nutrient supply would help maintain diets as the climate warms.

The recent United Nations call to action for blue transformation emphasizes the need to provide sufficient aquatic food from fisheries and aquaculture for our growing population in a sustainable way.

To do this, strategies are needed to achieve healthy, equitable and resilient food systems that adequately deal with overfishing, strive for equal access to resources and markets and mitigate the environmental impacts of aquatic food production.

Ultimately, these strategies must support the nutritional security of vulnerable nations and consider global health equity and the cultural significance of seafood.

Stefanie Colombo, Canada Research Chair in Aquaculture Nutrition, Dalhousie University and Aaron MacNeil, Professor, Department of Biology, Dalhousie University

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

Featured Image: (Pexels), CC BY

It’s now almost inevitable that 2023 will be the warmest year ever recorded by humans, probably the warmest for at least 125,000 years.

Multiple temperature records were smashed with global average temperatures for some periods well above 1.5°C. Antarctic sea ice loss is accelerating at frightening rates along with many other indicators of rapid climate change. Does this mean 2023 is the year parts of the climate tip into a much more dangerous state?

Most people expect that if a system, like someone’s body, an ecosystem, or part of the climate system, becomes stressed, it’ll respond fairly predictably – double the pressure, double the impact, and so on. This holds in many cases, but is not always true. Sometimes a system under stress changes steadily (or “linearly”) up to a point, but beyond that far bigger or abrupt changes can be locked in.

An example of such “nonlinear” changes are “tipping points”, which happen when a system is pushed past a threshold beyond which change becomes self-sustaining. This means that even if the original pressure eased off the change would keep on going until the system reaches a sometimes completely different state.

Think of rolling a boulder up a hill. This takes a lot of energy. If that energy input is stopped then the ball will roll back down. But when the top of the hill is reached and the boulder is balanced right at the very top, a tiny push, perhaps even a gust of wind, can be enough to send it rolling down the other side.

The climate system has many potential tipping points, such as ice sheets disappearing or dense rainforests becoming significantly drier and more open. It would be very difficult, effectively impossible, to recover these systems once they go beyond a tipping point.

We along with 200 other scientists from around the world just published the new Global Tipping Points Report at the COP28 UN climate talks in Dubai. Our report sets out the science on the “negative” tipping points in the Earth system that could harm both nature and people, as well as the potential “positive” societal tipping points that could accelerate sustainability action.

Here we look at the key messages from report sections on tipping points in the Earth system, their effects on people, and how to govern these changes.

Tipping points in air, land and sea

Having scoured scientific evidence of past and current changes, and factored in projections from computer models, we have identified over 25 tipping points in the Earth system.

Six of these are in the icebound parts of the planet (the “cryosphere”), including the collapse of massive ice sheets in Greenland and different parts of Antarctica, as well as localised tipping in glaciers and thawing permafrost. Sixteen are in the “biosphere” – the sum of all the world’s ecosystems – including trees dying on a massive scale in parts of the Amazon and northern boreal forests, degradation of savannas and drylands, nutrient overloading of lakes, coral reef mass mortality, and many mangroves and seagrass meadows dying off.

Photo by Daniel Seßler on Unsplash

Finally, we identified four potential tipping points in the circulation of the oceans and atmosphere, including collapse of deep ocean mixing in the North Atlantic and in the Southern Ocean around Antarctica, and disruption of the West African monsoon.

Human activities are already pushing some of these close to tipping points. The exact thresholds are uncertain, but at today’s global warming of 1.2°C, the widespread loss of warm water coral reefs is already becoming likely, while tipping in another four vital climate systems is possible. These are Greenland and West Antarctic ice sheet collapse, North Atlantic circulation collapse, and widespread localised thaw of permafrost.

Beyond 1.5°C several of these become likely, and other systems like mangroves, seagrass meadows, and parts of the boreal forest start to become vulnerable. Some systems can also tip or have their warming thresholds reduced due to other drivers, such as deforestation in the Amazon.

It can be hard to comprehend the consequences of crossing these tipping points. For example, if parts of the Amazon rainforest die, countless species would be lost, and warming would be further amplified as billions of tons of carbon currently locked up in trees and soils makes its way into the atmosphere. Within the region, this could cause trillions of dollars of economic impacts, and expose millions of people to extreme heat.

Given the sheer scale of risks from tipping points, you may assume that economic assessments of climate change include them. Alas, most assessments effectively ignore tipping point risks. This is perhaps the most frightening conclusion of the new report.

Human societies could tip into something much worse

There is also the potential for negative tipping in human societies, causing further financial instability, displacement, conflict or polarisation. These would hamper our efforts to limit further Earth system tipping points, and could even bring about a shift to a social system characterised by greater authoritarianism, hostility and alienation that could entirely derail sustainability transitions.

A further risk is that most of Earth’s tipping systems interact in ways that destabilise one another. In the worst case, tipping one system makes connected systems more likely to tip too. This could produce a “tipping cascade” like falling dominoes.

The Global Tipping Points Report makes clear that climate change is a key driver for most of these tipping points, and the risk of crossing them can be reduced by urgently cutting greenhouse gas emissions to zero (which “positive tipping points” could accelerate). To help prevent tipping points in the biosphere, we’ll also need to rapidly reduce habitat loss and pollution while supporting ecological restoration and sustainable livelihoods.

Ambitious new governance approaches are needed. Our report recommends international bodies like the UN’s climate talks urgently start taking tipping points into account. Their understanding of dangerous climate change needs a serious update.

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James Dyke, Associate Professor in Earth System Science, University of Exeter and David Armstrong McKay, Researcher in Earth System Resilience, Stockholm University

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

In a recent review of more than 180 peer-reviewed articles — which I conducted with fellow researcher Richard Parncutt — we found that a scientific consensus has formed around the so-called 1,000-ton rule.

The 1,000-ton rule states that a person is killed every time humanity burns 1,000 tons of fossil carbon. Shockingly, we found that a 2 C temperature rise equates to a billion prematurely dead people over the next century, killed as a result of a wide range of global warming related climate breakdowns.

These findings were derived from a review of the climate literature that attempted to quantify future human deaths from a long list of mechanisms.

This is a staggering body count, though however uncomfortable it may be, it is consistent with diverse evidence and arguments from multiple disciplines.

As world leaders gather for the COP28 climate conference in Dubai from Nov. 30-Dec. 12, we would do well to remember that their decisions will be directly responsible for killing, or saving, real human lives.

How climate change will kill us

Human-caused climate change has killed — and will continue to kill — many human beings by numerous climatic breakdowns caused through a complex web of direct, intermediate and indirect mechanisms.

Direct mortal effects of climate change include heat waves, which have already caused thousands of human deaths by a combination of heat and humidity and even threaten babies.

Intermediate causes of death involve crop failures, droughts, flooding, extreme weather, wildfires and rising seas. Crop failures, in particular, can make global hunger and starvation worse.

More frequent and severe droughts can lead to more wildfires that also cause human deaths, as we saw in Hawaii. Droughts can also lead to contaminated water, more frequent disease and deaths from dehydration.

The 2022 IPCC Report predicted that drought would displace 700 million people in Africa by 2030.

On the other hand, climate change can also cause flooding (and crop failures from too much water), which also drives hunger and disease. Climate change drives sea level rise and the resultant submersion of low-lying coastal areas and storm surges exacerbate flood risks, which are life-threatening for billions of people in coastal cities who face the prospect of forced migration.

Climate change also increases extreme weather events, which kill and cause considerable damage to essential services such as the electric grid and medical facilities. Salt water intrusion also threatens coastal agriculture, further reducing food supplies.

Finally, climate change also indirectly increases the probability of conflict and war. Although the academic consensus on climate-change-induced war is far from settled, there is little doubt climate change amplifies stress and can cause more localized conflict.

As the number of climate refugees increases, countries further from the equator might increasingly refuse to offer asylum. In a worst-case scenario, social collapse is possible and a Proceeding of the National Academy of Science article reports it could be devastating.

There is still time

A billion dead bodies is a scary prospect but not all of these deaths are predicted to occur at once. In fact, many people are already dying. However, there is still time to protect those remaining from also being killed by climate change by rapidly transitioning away from carbon energy sources.

We need to implement aggressive energy policies today to eliminate carbon emissions in energy conservation, encourage the evolution of the energy mix to renewable energy, and manage carbon waste. We are already doing a lot of this – we just need to do it faster.

Gradual decarbonization is not acceptable if it sacrifices such large numbers of human lives. And while each of these proposals may at first seem shocking, if we ask ourselves “would I accept this policy to save one billion human lives?” then I feel the answer becomes much clearer.

We must act to prevent the deaths of millions of our fellow human beings.

Not so radical

1. We must mandate all new construction be net-zero buildings or positive energy buildings. This would also have the bonus of providing building owners a positive return on investment and it is even possible to make them with no net cost.

2. Mandate mass purchases of energy conservation or renewable energy technologies and make them freely available to everyone with zero-interest loans that are easily paid back with energy savings. For example, a government could construct new factories to provide free insulation or solar panels to everyone that will take them. As an added bonus solar power will save homeowners money on electric bills as well as making major savings on energy conservation measures over their lifetimes.

3. Immediately end the sale of fossil fuel vehicles which will save considerable carbon and money as electric vehicles already have a lower lifetime cost than gas vehicles).

4. Revoke the charters of fossil fuel companies and disperse their assets if a company or industry is responsible for killing more people from emissions than they employ. It is a sobering fact that The United States coal industry already kills more people from air pollution per year than it employs, and that does not include climate change-related deaths.

5. Immediately stop investing in more fossil fuels and heavily tax all fossil fuel-related investments, and/or hold climate emitters as well as investors economically liable for harm caused by carbon emissions in the future.

6. Retrain fossil fuel workers en masse for renewable energy jobs which would help both society and workers who could expect an on average seven per cent pay rise moving to the solar industry.

7. Immediately ban the extraction of fossil fuels with enforced moratoriums.

Each of these seven policies will prevent an escalating amount of carbon from entering the atmosphere, preventing the concomitant climate change and billion premature deaths that would be caused by the status quo.

Moving forward

These policies can be achieved by targeting those first three actions that also directly align with economic savings. As economic replacements for fossil fuel technologies scale, the need for fossil fuel investment will continue its existing decline and pushing that decline further will become more politically palatable. As this is happening it will make sense to protect fossil fuel workers by retraining them so they can help accelerate the transition until all carbon-emitting fossil fuel use is ended to enable a stable climate.

Photo by Matt Palmer on Unsplash

This obviously is not going to be easy, but I believe that the vast majority of human beings are good people who will accept temporary inconveniences to transition to an energy system that will prevent one billion premature deaths.

Protecting these lives instead of sacrificing them would be an outcome from COP28 that demonstrates real leadership.

Joshua M. Pearce, John M. Thompson Chair in Information Technology and Innovation and Professor, Western University

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

The water off South Florida is over 90 degrees Fahrenheit (32 Celsius) in mid-July, and scientists are already seeing signs of coral bleaching off Central and South America. Particularly concerning is how early in the summer we are seeing these high ocean temperatures. If the extreme heat persists, it could have dire consequences for coral reefs.

Just like humans, corals can handle some degree of stress, but the longer it lasts, the more harm it can do. Corals can’t move to cooler areas when water temperatures rise to dangerous levels. They are stuck in it. For those that are particularly sensitive to temperature stress, that can be devastating.

I lead the Coral Program at the National Oceanic and Atmospheric Administration’s Atlantic Oceanographic and Meteorological Lab in Miami, Florida. Healthy coral reef ecosystems are important for humans in numerous ways. Unfortunately, marine heat waves are becoming more common and more extreme, with potentially devastating consequences for reefs around the world that are already in a fragile state.

Why coral reefs matter to everyone

Coral reefs are hot spots of biodiversity. They are often referred to as the rainforests of the sea because they are home to the highest concentrations of species in the ocean.

Healthy reefs are vibrant ecosystems that support fish and fisheries, which in turn support economies and food for millions of people. Additionally, they provide billions of dollars in economic activity every year through tourism, particularly in places like the Florida Keys, where people go to scuba dive, snorkel, fish and experience the natural beauty of coral reefs.

If that isn’t enough, reefs also protect shorelines, beaches and billions of dollars in coastal infrastructure by buffering wave energy, particularly during storms and hurricanes.

But corals are quite sensitive to warming water. They host a microscopic symbiotic algae called zooxanthella that photosynthesizes just like plants, providing food to the coral. When the surrounding waters get too warm for too long, the zooxanthellae leave the coral, and the coral can turn pale or white – a process known as bleaching.

If corals stay bleached, they can become energetically compromised and ultimately die.

When corals die or their growth slows, these beautiful, complex reef habitats start disappearing and can eventually erode to sand. A recent paper by John Morris, a scientist in my lab in Florida, shows that around 70% of reefs are now net erosional in the Florida Keys, meaning they are losing more habitat than they build.

Unfortunately, these critical coral reef habitats are in decline around the world because of extreme bleaching events, disease and numerous other human-caused stressors. In the Florida Keys, coral cover has decline by about 90% over the past several decades.

Coral bleaching in 2023

In the Port of Miami, where we have found particularly resilient coral communities, a doctoral candidate in my lab, Allyson DeMerlis, documented the first coral bleaching of her experimentally outplanted corals on July 11, 2023.

Other scientists we work with have reported coral bleaching off of Colombia, El Salvador, Costa Rica and Mexico in the eastern Pacific, as well as along the Caribbean coasts of Panama, Mexico and Belize.

We have yet to see widespread coral death associated with this particular marine heat wave, so it is possible the corals could recover if sea surface temperatures cool down soon. However, global sea surface temperatures are at record highs, and large parts of the Atlantic and eastern Pacific are under bleaching alerts. At this point, the evidence points to the potential for a very negative outcome.

El Niño is contributing to the problem this year, but the longer-term trends of rising ocean heat are driven by global warming fueled by human activities.

To put that into context, a paper by NOAA scientist Derek Manzello showed that in the Florida Keys, the number of days per year in which water temperatures were higher than 90 F (32 C) had increased by more than 2,500% in the two decades following the mid-1990s relative to the prior 20 years. That is a remarkable increase in the number of days that corals are experiencing particularly stressful warm water.

What can we do to protect corals?

First, we cannot give up on corals.

Alice Webb, a coral reef scientist working with our group, recently published a study based on years of our research in the Florida Keys. She modeled reef habitat persistence under climate, restoration and adaptation scenarios and found that protecting reefs is going to take everything – active restoration of reefs, helping corals acclimate or adapt to changing temperatures, and, importantly, human curbing of greenhouse gas emissions.

Major restoration efforts are underway in the Florida Keys as part of the NOAA-led Mission Iconic Reefs. We are also assessing how different coral individuals perform under stress, hoping to identify those that are particularly stress-tolerant by combing through the massive amounts of data from restoration projects and coral nurseries.

We are also evaluating stress-hardening techniques. For example, in tide pools, corals are exposed to large swings in temperature over short periods, making them more resilient to subsequent thermal stress events. We are exploring whether it’s possible to replicate that natural process in the lab, before corals are planted onto reefs, to better prepare them for stressful summers in the wild.

Coral bleaching on a large scale has really been documented only since the early 1980s. When I talk to people who have been fishing and diving in the Florida Keys since before I was born, they have amazing stories of how vibrant the reefs used to be. They know firsthand how bad things have become because they have lived it.

There isn’t currently a single silver-bullet solution, but ignoring the harm being done is not an option. There is simply too much at stake.

Ian Enochs, Research Ecologist, National Oceanic and Atmospheric Administration

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

Featured Image: Mass coral bleaching in 2014 left the Coral Reef Monitoring Program monitoring site at Cheeca Rocks off the Florida Keys a blanket of white.
NOAA

We use energy in everything we do, but few of us understand it properly. Much of the time this doesn’t matter. We can flick a light switch or turn the ignition key in a car, knowing the technology will work whether we understand it or not. Even something as simple as the distinction between alternating current and direct current is a mystery to most people without a scientific education.

But thanks to climate change, we can no longer be comfortably ignorant. A better understanding of energy systems is urgently needed if we are to transform those systems successfully.

Review: Powering Up: Unleashing the Clean Supply Energy Chain – Alan Finkel (Black Inc.)

The science of climate change is complex – too complex for any individual to comprehend completely. It encompasses physics, chemistry, time-series statistics and computer modelling, among many other issues. But by now, thanks to the work of communicators like the Intergovernmental Panel on Climate Change, most of us understand the basics.

The exception to this general understanding is the shrinking group of self-described “sceptics”, determined not to understand. Members of this group pride themselves on “doing their own research”. This catchphrase does not mean “undertaking years of intensive training in science and research methods, then applying it to the study of complex problems”, but rather “using Google to find talking points that confirm my prior beliefs”.

The central findings of climate research can be simply summarised. Over the course of the 20th century, we used more and more energy, the great majority of it derived from burning carbon-based fuels – oil, coal and natural (methane) gas. The result has been a buildup of carbon dioxide and other greenhouse gases in the atmosphere, trapping more of the Sun’s heat and radiating less back to outer space.

This process has already caused the global climate to heat up, with some disastrous results, such as wildfires and heatwaves. Global heating will inevitably continue, as will climate-related disasters. If we are to avoid truly catastrophic damage, we need a rapid transition to carbon-free sources of energy for electricity, transport and industrial uses.

A necessary guide

But which sources should we be pursuing, and is a rapid transition possible?

There are many issues to address. We must consider not only choices between technologies, but the balance between changing energy sources, promoting energy efficiency, and simply consuming less energy. As with the science of climate change, most of us lack the time and training to research these issues. We need a reliable guide.

Alan Finkel – formerly Australia’s chief scientist – has provided us with the guide we need. His new book, Powering Up, covers most of the issues relating to the energy transition in a way that is approachable and readable, without oversimplification.

The book begins by describing the magnitude of the energy transition we face. The process may be summed up very simply as “decarbonise electricity and electrify everything”. But that simple statement hides a great many complexities.

Nevertheless, Finkel argues, the massive reductions in the cost of solar photovoltaic cells and wind energy mean that the problem, while massive in scale, is economically manageable and will ultimately yield benefits.

Finkel gives an accessible explanation of the distinction between energy (the ability of a system to do things) and power (how quickly energy is generated and used). This is important in understanding variable energy sources, such as solar, and in explaining energy storage systems, such as batteries.

Critical minerals

The first two chapters of Powering Up deal with the minerals required for the energy transition, often referred to as “critical minerals”. These minerals have been the subject of many hand-wringing opinion pieces about inadequate supply and the damage caused by mining. However, as Finkel shows, most of these worries are misplaced. So-called “rare earths”, for example, are neither rare nor earths.

The only really problematic case is that of cobalt, mostly produced in the Democratic Republic of Congo by an industry that employs around 200,000 workers, many of them children, under appalling conditions.

This is a big problem, but there are ways to resolve it. Most obviously, the companies that mine the cobalt could pay their workers a living wage – as some, at least, have promised to do. If workers were paid US$10,000 a year, well above the average for Africa as a whole, the total wage bill would only be $2 billion a year, a trivial amount in the context of the global energy economy.

Alternatively, as Finkel shows, it would be possible to source cobalt from other countries, including Australia, or to switch to somewhat less efficient technologies based on manganese. The lesson of history is that, just as “the cemetery is full of indispensable men”, there is no single mineral so critical that civilisation would grind to a halt without it.

The next two chapters focus on the core of the transition to an electricity system based on solar photovoltaic and wind generation. This would need to be backed up by batteries, pumped hydro, and other technologies for “firming” (dealing with short-run fluctuations) and storage (dealing with mismatches between the time electricity is generated, and the time it is needed).

In this context, “renewable” is a somewhat unfortunate term – what matters is low emissions. In particular, the term excludes nuclear power and allows potentially problematic sources, such as burning biomass.

However, as Finkel observes, nuclear power is no longer a relevant issue for Australia. There is no prospect of nuclear power here before 2040, by which time all coal-fired plants will be closed, and gas will play at most a marginal role. Globally, it makes sense to extend the lives of existing nuclear plants, but new nuclear power can’t compete with the combination of renewables and storage.

Getting the transition right is a complex problem. Finkel discusses the sorry history of energy policy over the past decade or so (a period in which we worked together as members of the Climate Change Authority). This period of failure included the rejection of the Clean Energy Target, which he recommended to the Turnbull government, and the creation of the misnamed and misbegotten Energy Security Board, now thankfully abolished.

Finkel considers what might emerge from the current rather chaotic situation, in which a variety of government initiatives interact with the remains of the artificial electricity market that emerged from the reforms of the 1990s. Looking to the future, he provides a guide to the exciting possibilities of the hydrogen economy, and the opportunity to use Australia’s massive endowment of sun and wind as the basis of an energy export industry to replace coal and gas.

This would include a revived “green” steel industry, in which direct reduction of iron ore using hydrogen would replace the blast-furnace technology that has been dominant since the 19th century. A hydrogen-based steel industry will require the use of magnetite, the highest-quality form of iron ore, with which we are also well endowed.

One disappointment in this chapter is Finkel’s failure to give adequate weight to direct export of electricity using high-voltage direct current. Projects such as Sun Cable, which aims to export Australian electricity to Singapore and other destinations, seem at least as promising as hydrogen.

Finkel concludes with a discussion of some of the complex political and social issues surrounding the energy transition in Australia and globally. His treatment of these issues is measured and sensible, but doesn’t match the depth of his analysis of the technical issues in the main body of the book. It would be wonderful to have a summary of the policy issues as accessible and comprehensive as Finkel’s overview of the technological issues.

In the meantime, this is a book that everyone interested in the energy transition should read.

John Quiggin, Professor, School of Economics, The University of Queensland

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Featured Image: Andrey Metelev/Unsplash, CC BY-SA

Across the world, rainforests are becoming savanna or farmland, savanna is drying out and turning into desert, and icy tundra is thawing. Indeed, scientific studies have now recorded “regime shifts” like these in more than 20 different types of ecosystem where tipping points have been passed. Across the world, more than 20% of ecosystems are in danger of shifting or collapsing into something different.

These collapses might happen sooner than you’d think. Humans are already putting ecosystems under pressure in many different ways – what we refer to as stresses. And when you combine these stresses with an increase in climate-driven extreme weather, the date these tipping points are crossed could be brought forward by as much as 80%.

This means an ecosystem collapse that we might previously have expected to avoid until late this century could happen as soon as in the next few decades. That’s the gloomy conclusion of our latest research, published in Nature Sustainability.

Human population growth, increased economic demands, and greenhouse gas concentrations put pressures on ecosystems and landscapes to supply food and maintain key services such as clean water. The number of extreme climate events is also increasing and will only get worse.

What really worries us is that climate extremes could hit already stressed ecosystems, which in turn transfer new or heightened stresses to some other ecosystem, and so on. This means one collapsing ecosystem could have a knock-on effect on neighbouring ecosystems through successive feedback loops: an “ecological doom-loop” scenario, with catastrophic consequences.

How long until a collapse?

In our new research, we wanted to get a sense of the amount of stress that ecosystems can take before collapsing. We did this using models – computer programs that simulate how an ecosystem will work in future, and how it will react to changes in circumstance.

We used two general ecological models representing forests and lake water quality, and two location-specific models representing the Chilika lagoon fishery in the eastern Indian state of Odisha and Easter Island (Rapa Nui) in the Pacific Ocean. These latter two models both explicitly include interactions between human activities and the natural environment.

The key characteristic of each model is the presence of feedback mechanisms, which help to keep the system balanced and stable when stresses are sufficiently weak to be absorbed. For example, fishers on Lake Chilika tend to prefer catching adult fish while the fish stock is abundant. So long as enough adults are left to breed, this can be stable.

Image by ANIL GOPI from Pixabay

However, when stresses can no longer be absorbed, the ecosystem abruptly passes a point of no return – the tipping point – and collapses. In Chilika, this might occur when fishers increase the catch of juvenile fish during shortages, which further undermines the renewal of the fish stock.

We used the software to model more than 70,000 different simulations. Across all four models, the combinations of stress and extreme events brought forward the date of a predicted tipping point by between 30% and 80%.

This means an ecosystem predicted to collapse in the 2090s owing to the creeping rise of a single source of stress, such as global temperatures, could, in a worst-case scenario, collapse in the 2030s once we factor in other issues like extreme rainfall, pollution, or a sudden spike in natural resource use.

Importantly, around 15% of ecosystem collapses in our simulations occurred as a result of new stresses or extreme events, while the main stress was kept constant. In other words, even if we believe we are managing ecosystems sustainably by keeping the main stress levels constant – for example, by regulating fish catches – we had better keep an eye out for new stresses and extreme events.

There are no ecological bailouts

Previous studies have suggested significant costs from going past tipping points in large ecosystems will kick in from the second half of this century onwards. But our findings suggest these costs could occur much sooner.

We found the speed at which stress is applied is vital to understanding system collapse, which is probably relevant to non-ecological systems too. Indeed, the increased speed of both news coverage and mobile banking processes has recently been invoked as raising the risk of bank collapse. As the journalist Gillian Tett has observed:

The collapse of Silicon Valley Bank provided one horrifying lesson in how tech innovation can unexpectedly change finance (in this case by intensifying digital herding). Recent flash crashes offer another. However, these are probably a small foretaste of the future of viral feedback loops.

But there the comparison between ecological and economic systems runs out. Banks can be saved as long as governments provide sufficient financial capital in bailouts. In contrast, no government can provide the immediate natural capital needed to restore a collapsed ecosystem.

There is no way to restore collapsed ecosystems within any reasonable timeframe. There are no ecological bailouts. In the financial vernacular, we will just have to take the hit.

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John Dearing, Professor of Physical Geography, University of Southampton; Gregory Cooper, Postdoctoral Research Fellow in Social-Ecological Resilience, University of Sheffield, and Simon Willcock, Professor of Sustainability, Bangor University

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Greater conservation efforts are needed to protect Antarctic ecosystems, and the populations of up to 97% of land-based Antarctic species could decline by 2100 if we don’t change tack, our new research has found.

The study, published today, also found just US$23 million per year would be enough to implement ten key strategies to reduce threats to Antarctica’s biodiversity.

This relatively small sum would benefit up to 84% of terrestrial bird, mammal, and plant groups.

We identified climate change as the biggest threat to Antarctica’s unique plant and animal species. Limiting global warming is the most effective way to secure their future.

Threats to Antarctic biodiversity

Antarctica’s land-based species have adapted to survive the coldest, windiest, highest, driest continent on Earth.

The species includes two flowering plants, hardy moss and lichens, numerous microbes, tough invertebrates and hundreds of thousands of breeding seabirds, including the emperor and Adélie penguins.

Antarctica also provides priceless services to the planet and humankind. It helps regulate the global climate by driving atmospheric circulation and ocean currents, and absorbing heat and carbon dioxide. Antarctica even drives weather patterns in Australia.

Some people think of Antarctica as a safe, protected wilderness. But the continent’s plants and animals still face numerous threats.

Chief among them is climate change. As global warming worsens, Antarctica’s ice-free areas are predicted to expand, rapidly changing the habitat available for wildlife. And as extreme weather events such as heatwaves become more frequent, Antarctica’s plants and animals are expected to suffer.

What’s more, scientists and tourists visiting the icy continent each year can harm the environment through, for example, pollution and disturbing the ground or plants. And the combination of more human visitors and milder temperatures in Antarctica also creates the conditions for invasive species to thrive.

So how will these threats affect Antarctic species? And what conservation strategies can be used to mitigate them? Our research set out to find the answers.

What we found

Our study involved working with 29 experts in Antarctic biodiversity, conservation, logistics, tourism and policy. The experts assessed how Antarctica’s species will respond to future threats.

Under a worst-case scenario, the populations of 97% of Antarctic terrestrial species and breeding seabirds could decline between now and 2100, if current conservation efforts stay on the same trajectory.

At best, the populations of 37% of species would decline. The most likely scenario is a decline in 65% of the continent’s plants and wildlife by the year 2100.

The emperor penguin relies on ice for breeding, and is the most vulnerable of Antarctica’s species. In the worst-case scenario, the emperor penguin is at risk of extinction by 2100 – the only species in our study facing this fate.

Climate change will also likely wreak havoc on other Antarctic specialists, such as the nematode worm Scottnema lindsayae. The species lives in extremely dry soils, and is at risk as warming and ice-melt increases soil moisture.

Climate change won’t lead to a decline in all Antarctic species – in fact, some may benefit initially. These include the two Antarctic plants, some mosses and the gentoo penguin.

These species may increase their populations and become more widely distributed in the event of more liquid water (as opposed to ice), more ice-free land and warmer temperatures.

So, what to do?

Clearly, current conservation efforts are insufficient to conserve Antarctic species in a changing world.

The experts we worked with identified ten management strategies to mitigate threats to the continent’s land-based species.

Unsurprisingly, mitigating climate change (listed as the “influence external policy” strategy) would provide the greatest benefit. Reducing climate change to no more than 2℃ of warming would benefit up to 68% of terrestrial species and breeding seabirds.

The next two most beneficial strategies were “managing non-native species and disease” and “managing and protecting species”. These strategies include measures such as granting special protections to species, and increasing biosecurity to prevent introductions of non-native species.

How much would it all cost?

The United Nations’ COP15 nature summit concluded in Canada this week. Funding for conservation projects was a core agenda item.

In Antarctica, at least, such conservation is surprisingly cheap. Our research found implementing all strategies together could cost as little as US$23 million per year until 2100 (or about US$2 billion in total).

By comparison, the cost to recover Australia’s threatened species is estimated at more than US$1.2 billion per year (although this is far more than is actually spent).

However, for the “influence external policy” strategy (relating to climate change mitigation) we included only the cost of advocating for policy change. We did not include the global cost of reducing carbon emissions, nor did we balance these against the much greater economic costs of not acting.

As Antarctica faces increasing pressure from climate change and human activities, a combination of regional and global conservation efforts is needed. Spending just US$23 million a year to preserve Antarctica’s biodiversity and ecosystems is an absolute bargain.

Jasmine Lee, Conservation biologist, Queensland University of Technology; Iadine Chadès, Principal research scientist, CSIRO, and Justine Shaw, Conservation Biologist, The University of Queensland

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