If a person's temperature rises from 36,6 to 38,6 degrees Celsius - there are consequences. Even a seemingly small increase causes that person to feel uncomfortable and the body can no longer function normally. It is similar with the planet Earth.
Since the end of the 19th century, when the burning of fossil fuels began to progress, our planet has warmed on average by more than one degree, and in some places temperatures have risen above that value.
One of them is the Arctic. According to the Arctic Monitoring and Assessment Program (AMAP), a working group of the intergovernmental Arctic Council, the average annual temperature in the region increased by three degrees Celsius between 1971 and 2019 - and this poses major problems for the region's ecosystem.
Small rise in temperature - big loss of species
In a study published this year in the journal "Cryosphere", British researchers show a loss of 28 trillion tons of ice between 1994 and 2017. According to their data, the lost volume would be enough to cover the entire Great Britain with a layer of ice a hundred meters thick.
Scientists from the University of Edinburgh, University College London and the University of Leeds used satellite data to conclude that in the 90s, about 800 billion tonnes of ice was lost annually. By 2017, that number had even increased - to 1,2 trillion tons per year.
Polar bears will be extinct by the end of the century?
Steven Amstrup, a scientist from the American conservation organization Polar Bears International, has been researching wildlife in the Arctic since the 1980s and has seen the changes with his own eyes.
“I remember seeing sea ice on the coast of northern Alaska in the middle of summer - it was never far from shore. Now the ice at the same time of the year is hundreds of miles from the sea. If you had said something like that to me at the beginning of my career, I would have said you were crazy," says Amstrup.
In a 2020 study published in the Nature Climate Journal, he and his colleagues predict that most of the polar bears that feed on seals could disappear by the end of the century if temperatures continue to rise. "The sandbars where the seals rest are like the polar bears' dinner table," says Amstrup. "There is hardly anything on land as nutritious for them as seals."
The United Nations Intergovernmental Panel on Climate Change (IPCC) predicts that, with global warming of 1,5 degrees Celsius above pre-industrial levels, Arctic animals will still have ice for 99 out of 100 summers. In a two-degree warming scenario, they would face ice-free summers every ten years.
Polar bears are by no means the only victims of global warming. For 19 percent of animal species on the Red List of the International Union for Conservation of Nature (IUCN), the probability of extinction is increasing.
One species has already been destroyed: the tiny rodent Melomys rubicola who lived on a small sandy island at the tip of the Great Barrier Reef in northeastern Australia. It was officially recognized as an extinct species in 2019 - the first mammal to disappear due to human-caused climate change. Rising sea levels are believed to have destroyed its food sources and habitat.
Extreme consequences below and above water
With global warming, the oceans are also warming - with direct effects on coral reefs that are nurseries and storage areas for many marine animals. Warmer water causes corals to shed vital seaweed from their tissues - and then starve and dry out, leading to bleaching. This will destroy the corals in the long run.
Recent research has shown that Australia's Great Barrier Reef has lost half of its corals in this way since 1995. The Intergovernmental Panel on Climate Change warns that if the temperature rises above 2 degrees Celsius, corals will be almost completely eradicated.
Higher temperatures will also change people's lives. We will face more extreme weather conditions: heat waves, droughts, floods and cyclones. How extreme and how often will depend on how much temperatures rise.
If the world warms by two degrees Celsius by 2100, 37 percent of the world's population could be exposed to severe heat waves at least every five years, according to the IPCC. In a 1,5 degree scenario, it would affect half as many people.
According to a 2018 study by the European Commission's Joint Research Center (JRC) for Science and Knowledge, two-thirds of the population will experience increasing droughts as the world warms.
More climate refugees
The UN Refugee Agency estimates that extreme weather conditions and rising sea levels already force more than 20 million people to move to other parts of their countries every year. Resettlement is already a problem for small island nations in the Pacific and Indian Oceans, as well as in the Caribbean.
"Countries like the Marshall Islands can implement adaptation plans up to a certain level of sea level rise," says Helene Jacot de Combe, a climatologist at the University of the South Pacific, an IPCC author and adviser to the Marshall Islands government. "But if it continues to grow, at some point those islands will no longer be habitable."
The Pacific island nation of Fiji is also facing a new reality. After being hit by twelve cyclones and other extreme weather events since 2016, the government has started a resettlement program. More than 40 coastal communities have to move inland, and six have already done so.
Given the far-reaching consequences of even a small increase in temperature, the Paris Climate Agreement aims to limit the global increase to 1,5 degrees Celsius this century. However, model calculations suggest that, given current trends, the world is well on its way to reaching that level of warming as early as the next 15 years.
Without radical measures today, the rise in temperature will hardly be slowed down. According to The Climate Action Tracker, an independent group of organizations that analyzes government climate action, by the end of this century temperatures would rise to 2 to 2,2 degrees Celsius, even if all current pledges and plans were implemented across the board. world filled. At the same time, this group estimates that this is an optimistic forecast.
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