As renewable energy production expands across the U.S., the environmental impacts of these new sources are receiving increased attention. In a recent report, the National Academies of Sciences, Engineering, and Medicine examined whether and how constructing offshore wind farms in the Nantucket Shoals region, southeast of Massachusetts, could affect critically endangered North Atlantic right whales. The Conversation asked marine scientists Erin L. Meyer-Gutbrod, Douglas Nowacek, Eileen E. Hofmann and Josh Kohut, all of whom served on the study committee, to explain the report’s key findings.
PFAS, the “forever chemicals” that have been raising health concerns across the country, are not just a problem in drinking water. As these chemicals leach out of failing septic systems and landfills and wash off airport runways and farm fields, they can end up in streams that ultimately discharge into ocean ecosystems where fish, dolphins, manatees, sharks and other marine species live.
We study the risks from these persistent pollutants in coastal environments as environmentalanalytical chemists at Florida International University’s Institute of the Environment.
Human-driven climate change is increasingly shaping the Earth’s living environments. Rising temperatures, rapid shifts in rainfall and seasonality, and ocean acidification are presenting altered environments to many animal species. How do animals adjust to these new, often extreme, conditions?
Animal nervous systems play a central role in both enabling and limiting how they respond to changing climates. As a biologist and neuroscientist, two of my main research interests involve understanding how animals accommodatetemperature extremes and identifying the forces that shape the structure and function ofanimal nervous systems, especially brains. The intersection of these interests led me to explore the effects of climate on nervous systems and how animals will likely respond to rapidly shifting environments.
All major functions of the nervous system – sense detection, mental processing and behavior direction – are critical. They allow animals to navigate their environments in ways that enable their survival and reproduction. Climate change will likely affect these functions, often for the worse.
Shifting sensory environments
Changing temperatures shift the energy balance of ecosystems – from plants that produce energy from sunlight to the animals that consume plants and other animals – subsequently altering the sensory worlds that animals experience. It is likely that climate change will challenge all of their senses, from sight and taste to smell and touch.
Animals like mammals perceive temperature in part with special receptor proteins in their nervous systems that respond to heat and cold, discriminating between moderate and extreme temperatures. These receptor proteins help animals seek appropriate habitats and may play a critical role in how animals respond to changing temperatures.
Climate change disrupts the environmental cues animals rely on to solve problems like selecting a habitat, finding food and choosing mates. Some animals, such as mosquitoes that transmit parasites and pathogens, rely on temperature gradients to orient themselves to their environment. Temperature shifts are altering where and when mosquitoes search for hosts, leading to changes in disease transmission.
Climate change is pushing more and more mosquitoes to take humans as their preferred hosts.
How climate change affects the chemical signals animals use to communicate with each other or harm competitors can be especially complex because chemical compounds are highly sensitive to temperature.
Formerly reliable sources of information like seasonal changes in daylight can lose its utility as they become uncoupled. This could cause a breakdown in the link between day length and plant flowering and fruiting, and interruptions to animal behavior like hibernation and migration when day length no longer predicts resource availability.
Changing brains and cognition
Rising temperatures may disrupt how animal brains develop and function, with potentially negative effects on their ability to effectively adapt to their new environments.
In marine environments, researchers have found that climate-induced changes of water chemistry like ocean acidification can affect animals’ general cognitive performance and sensory abilities, such as odor tracking in reef fish and sharks.
Activity can also shift to different periods of the dayor tonew seasons. These behavioral responses can have major implications for the environmental stimuli animals will be exposed to.
Shifting climates are driving some snake species into forested habitats, and the subsequent increased predation on nesting birds may push above sustainable levels. Rapeepong Puttakumwong/Moment via Getty Images
For example, fish in warming seas have shifted to cooler, deeper waters that have dramatically different light intensity and color range than their visual systems are used to. Furthermore, because not all species will shift their behaviors in the same way, species that do move to a new habitat, time of day or season will confront new ones, including food plants and prey animals, competitors and predators, and pathogens.
Behavioral shifts driven by climate change will restructure ecosystems worldwide, with complex and unpredictable outcomes.
But studies comparing species have seen strongenvironmental effects on brain evolution. Animal nervous systems evolve to match the sensory environments of each species’ activity space. These patterns suggest that new climate regimes will eventually shape nervous systems by forcing them to evolve.
When genetics have strong effects on brain development, nervous systems that are finely adapted to the local environment may lose their adaptive edge with climate change. This may pave the way for new adaptive solutions. As the range and significance of sensory stimuli and seasonal cues shift, natural selection will favor those with new sensory or cognitive abilities.
Some parts of the nervous system are constrained by genetic adaptations while others are more plastic and responsive to environmental conditions. A greater understanding of how animal nervous systems adapt to rapidly changing environments will help predict how all species will be affected by climate change.
Sean O'Donnell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
When this year’s United Nations Climate Change Conference begins in late November 2023, it will be a moment for course correction. Seven years ago, nearly every country worldwide signed onto the Paris climate agreement. They agreed to goals of limiting global warming – including key targets to be met by 2030, seven years from now.
A primary aim of this year’s conference, known as COP28, is to evaluate countries’ progress halfway to the 2030 deadlines.
Reports show that the world isn’t on track. At the same time, energy security concerns and disputes over how to compensate countries for loss and damage from climate change are making agreements on cutting emissions tougher to reach.
A cornerstone of COP28 is the conclusion of the global stocktake, a review underway of the world’s efforts to address climate change. It is designed to pinpoint deficiencies and help countries recalibrate their climate strategies.
A report on the stocktake so far stressed that while the Paris Agreement has spurred action on climate change around the globe, current policies and promises to cut greenhouse gas emissions still leave the world on a trajectory that falls far short of the agreement’s aim to limit warming to less than 1.5 degrees Celsius (2.7 Fahrenheit) compared with preindustrial temperatures.
Governments worldwide plan to produce twice as much fossil fuel in 2030 than would be allowed under a 1.5 C warming pathway, another U.N.-led report released in early November found.
Limiting global warming to 1.5 C rather than 2 C (3.6 F), may appear to be a minor improvement, but the accumulated global benefits of doing so could exceed US$20 trillion.
Escalating greenhouse gas emissions are the primary factor driving the rise in global temperatures. And fossil fuels account for over three-quarters of those emissions.
To avoid overshooting 1.5 C of warming, global greenhouse gas emissions will have to fall by about 45% by 2030, compared with 2010 levels, and reach net zero around 2050, according to the Intergovernmental Panel on Climate Change.
But emissions aren’t falling. They rose in 2022, surpassing pre-pandemic levels. The global average temperature briefly breached the 1.5 C warming limit in March and June 2023.
A line chart of daily temperatures since 1940, by month, shows how extreme 2023’s temperatures have been. Years before 2014 are in gray. European Union Earth Observation Program
The global stocktake unambiguously states that, to meet the Paris targets, countries must collectively be more ambitious in cutting greenhouse gas emissions. That includes rapidly reducing carbon emissions from all economic sectors. It means accelerating adoption of renewable energy such as solar and wind power, implementing more stringent measures to stop and reverse deforestation, and deploying clean technologies such as heat pumps and electric vehicles on a wide scale.
The significance of phasing out fossil fuels
The report underscores one point repeatedly: the pressing need to “phase out all unabated fossil fuels.”
Fossil fuels currently make up 80% of the world’s total energy consumption. Their use in 2022 resulted in an all-time high of 36.8 gigatons of CO2 from both energy combustion and industrial activities.
Despite the risks of climate change, countries still provide huge subsidies to the oil, coal and gas industries. In all, they provided about US$1.3 trillion in explicit subsidies for fossil fuels in 2022, according to the International Monetary Fund’s calculations. China, the U.S., Russia, the European Union and India are the largest subsidizers, and these subsidies sharply increased after Russia’s invasion of Ukraine in 2022 disrupted energy markets.
U.N. Secretary-General António Guterres has stressed the importance of transitioning away from fossil fuels, criticizing the extensive profits made by “entrenched interests” in the fossil fuel sector.
African countries also made their view of subsidies clear in the “Nairobi Declaration” at the first Africa Climate Summit in 2023, where leaders called for the elimination of inefficient fossil fuel subsidies and endorsed the idea of a global carbon tax on fossil fuel trade.
The global stocktake highlights the significance of eradicating fossil fuel subsidies to eliminate economic roadblocks that hinder the shift to greener energy sources. However, it’s important to note that the report uses the phrase “unabated fossil fuels.” The word “unabated” has been contentious. It allows room for continued use of fossil fuels, as long as technologies such as carbon capture and storage prevent emissions from entering the atmosphere. But those technologies aren’t yet operating on a wide scale.
Solutions for an equitable transition
Several initiatives have been launched recently to expedite the move away from fossil fuels.
In July 2023, Canada unveiled a strategy to terminate inefficient fossil fuel subsidies, becoming the first G20 nation to pledge a halt to government support for oil and natural gas, with some exceptions.
The European Union is broadening its carbon market to include emissions from buildings and transport, targeting decarbonization across more sectors. Concurrently, the United States’ Inflation Reduction Act commits US$10 billion to clean energy projects and offers $4 billion in tax credits to communities economically affected by the coal industry’s decline.
To help low-income countries build sustainable energy infrastructure, a relatively new financing mechanism called Just Energy Transition Partnerships is gaining interest. It aims to facilitate cooperation, with a group of developed countries helping phase out coal in developing economies that are still reliant on fossil fuels.
South Africa, Indonesia, Senegal and Vietnam have benefited from these partnerships since the first was launched in 2021. The European Union, for instance, has pledged to support Senegal’s shift from fossil fuels to renewable energy. This includes managing the economic fallout, such as potential job losses, from shutting down fossil fuel power plants, while ensuring electricity remains affordable and more widely available.
A just transition takes into account a future for coal miners, like these men headed for a South African coal mine. Luca Sola/AFP via Getty Images
By COP28, a comprehensive plan to help Senegal aim for a sustainable, low-emissions future should be in place. France, Germany, Canada and various multilateral development banks have promised to provide 2.5 billion Euros (about US$2.68 billion) to increase Senegal’s renewable energy output. The goal is for renewables to account for 40% of Senegal’s energy use by 2030.
To align with the Paris Agreement objectives, we believe global initiatives to reduce fossil fuel dependency and invest in developing nations’ sustainable energy transition are essential. Such endeavors not only champion reducing greenhouse gas emissions but also ensure economic growth in an environmentally conscious manner.
The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
