Global warming is spiralling out of control: Earth could warm by a whopping 7°C by 2200, scientists...
Our not-too-distant future relatives could be in for a rough ride - even if we manage to curb our carbon emissions, a new study suggests. Earth could warm by a whopping 7C (12.6F) by 2200 even if CO2 emissions are moderate, according to scientists at 's Potsdam Institute for Climate Impact Research (PIK). Conditions would be too hot for common crops to grow properly, which would cause global food insecurity and even starvation. Meanwhile, rising sea levels due to melting ice would force people to flee coastal cities as a result of flooding. Also under such a scenario, intense extreme weather events such as drought, heatwaves, wildfires, tropical storms and flooding would be common. Especially in the summer, temperatures could reach dangerously high levels, posing a lethal threat to the people of all ages. Lead study author Christine Kaufhold at PIK said the findings highlight an 'urgent need for even faster carbon reduction and removal efforts'. 'We found that peak warming could be much higher than previously expected under low-to-moderate emission scenarios,' she said. Planet-warming greenhouse gases such as carbon dioxide (CO2) and methane are largely being released by burning fossil fuels such as coal and gas for energy. But greenhouse gas emissions come from natural processes too, such as volcanic eruptions, plant respiration and animals' breathing which is why they call for . For the study, the team used their own newly developed computer model, called CLIMBER-X, to simulate future global warming scenarios. It integrates key physical, biological and geochemical processes, including atmospheric and oceanic conditions that involve methane. Even more potent than carbon dioxide (CO2), methane sources include the decomposition of landfill waste and natural emissions from wetlands. The model considered three scenarios, called 'Shared Socioeconomic Pathways' (SSPs), based on low, medium and high projected global emission levels throughout the rest of this millennium. According to the experts, most climate studies until now only predict as far into the future as 2300 which may not represent 'peak warming'. According to the findings, there's a 10 per cent chance that Earth will still warm by 3C (5.4F) by 2200 even if emissions begin to decline now. The team say global heating over this millennium could exceed previous estimates due to 'carbon cycle feedback loops' where one change to the climate amplifies another which are being overlooked. For example, rainy weather fuels the growth of certain flammable grass, which . Another example is the additional CO2 release from permafrost (where thawing soil will release more of the gas). Worryingly, reducing emissions in the future may not be enough to limit these feedback processes, as already emitted greenhouse gases may continue to have lasting effects on the worlds temperature. What's more, achieving the Paris Agreement's aim of limiting global temperature rise to well below 2C (3.6F) is only feasible under very low emissions scenarios. Signed in 2015, the landmark binding international treaty aims to keep global temperature increases below 2.7F (1.5C). But according to the team, the window for limiting global warming to below 2C is 'rapidly closing'. 'Carbon reduction must accelerate even more quickly than previously thought to keep the Paris target within reach,' said PIK scientist Matteo Willeit, study co-author. The new study, published in , highlights 'uncertainties in projecting future climate change'. 'Our research makes it unmistakably clear today's actions will determine the future of life on this planet for centuries to come,' said co-author and PIK director Johan Rockstrom. 'We are already seeing signs that Earth system is losing resilience, which may trigger feedbacks that increase climate sensitivity, accelerate warming and increase deviations from predicted trends. 'To secure a liveable future, we must urgently step up our efforts to reduce emissions. 'The Paris Agreement's goal is not just a political target, it is a fundamental physical limit.'