Global heating is dangerously close to being out of control with humans “unequivocally” to blame, the world’s leading climate scientists warn.
A new report by the UN’s Intergovernmental Panel on Climate Change is the starkest alarm bell yet about the speed and scale of the climate emergency, with recent effects from floods to heatwaves.
Drawing on 14,000 scientific studies, it gives the most “devastating” picture yet of the impacts humans are having through activities like burning fossil fuels – and the future we faces if we fail to rapidly tackle the crisis. Its summary reads: “It is unequivocal that human influence has warmed the atmosphere, ocean and land.”
Previous IPCC reports only said it was “extremely likely” that industrial activity was to blame, but co-author Friederike Otto, a climatologist at Oxford University, said: “There is no uncertainty language in this sentence, because there is no uncertainty that global warming is caused by human activity and burning of fossil fuels.”
UN Secretary-General Antonio Guterres called it a “code red for humanity”, adding: “The alarm bells are deafening. This report must sound a death knell for coal and fossil fuels, before they destroy our planet.”
A 2018 interim report said global warming was likely to reach 1.5C – a limit countries agreed under the Paris Agreement – between 2030 and 2052. This report brings this window forward to 2021 to 2040.
The future is not yet written and the very worst of climate change is still avoidable.
Although we are rapidly heading towards “devastating” global warming, the report shows that keeping that rise at 1.5 degrees is achievable.
The most important thing you can do is by making changes to reduce your own personal CO2 emissions.
You can do this by:
1 Flying is a major source of carbon pollution. Not everyone has the privilege of flying but if you do, taking a few less flights is one of the best ways of dramatically reducing your carbon footprint.
2 Drive less and cycle or walk more. Make your next car purchase an electric vehicle. Your purchase will significantly reduce your carbon pollution and improve local air quality.
3 Install solar panels to generate energy for your home. Ensure you have good insulation which will dramatically reduce your emissions and your bills. Switch to a green energy supplier.
4 Don’t waste food which is responsible for about 10% of emissions.
Downsize your weekly, freeze leftovers and set up a compost system for food waste.
5 Reduce your intake of high-carbon meat and dairy products by 20% by 2030, with further reductions in later years. If the whole of the country cut out meat just one day a week, scientists say it would be the equivalent of taking 16 million cars off the road.
Greenhouse gas levels are already high enough to disrupt the climate for decades, it said, with weather extremes becoming more severe. It also warns that climate change is affecting every region on Earth and that without urgent action, the loss of summer Arctic Sea ice will increase while carbon sinks like the Amazon will weaken.
It says cutting global emissions to net zero by mid-century would give a good chance of limiting warming to 1.5C in the long term and help avoid the worst effects.
Professor Albert Klein Tank, director of the Met Office Hadley Centre, said: “Time is short to avert the worst impacts.”
In November, the UN COP26 conference in Glasgow will aim to encourage more ambitious global climate action.
Professor Stephen Belcher, Met Office chief scientist, said the report is “overwhelming evidence to delegates that without urgent action we won’t avoid the worst impacts of climate change”.
Bob Ward, of the Grantham Research Institute on Climate Change, said “increasing frequency and intensity of heatwaves, heavy rainfall and wildfires… are exactly the consequences warned about in previous IPCC reports”. He added: “We ignore this new report at our peril.”
(
Image:
Getty Images/iStockphoto)
Human activity is responsible
The report goes well beyond the previous IPCC assessment of 2013 and resolves all major uncertainties, to provide the clearest picture yet of the effect of human activities on the climate and on weather extremes.
It explains how as long as we continue to emit CO2 the climate will continue to warm and the weather extremes – which the world has been experiencing – will continue to intensify.
It makes clear that human-caused climate change, such as a reliance on fossil fuels, which has pushed up global temperatures by 1.1C, is driving weather and climate extremes in every region across the world.
One of the report’s lead authors, Dr Tamsin Edwards, from King’s College London, said: “Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, the 1.5C target will be beyond reach.
(
Image:
Getty Images)
Weather getting more extreme
Events once considered rare or unprecedented are becoming more common – a trend that will continue even if global heating is limited to 1.5C.
Severe heat waves that happened only once every 50 years are now happening roughly once a decade. Tropical cyclones are getting stronger.
Most land areas are seeing more rain or snow fall in a year. Severe droughts are happening 1.7 times as often. And fire seasons are getting longer and more intense.
Heavy precipitation and flooding will also become “more intense and frequent” in Europe due to climate change. Very wet and dry weather systems will also be intensified with implications for flooding and drought when this occurs.
The report adds: “Several regions in Africa, South America and Europe are projected to experience an increase in frequency and/or severity of agricultural and ecological droughts with medium to high confidence.”
Sea levels will continue to rise
Even if global warming were halted at 1.5C, the average sea level would still rise about 2 to 3 meters (6 to 10 feet), and maybe more.
Sea level rise has picked up speed, as polar ice sheets melt and warming ocean water expands. Already, associated flooding has nearly doubled in many coastal areas since the 1960s, with once-in-a-century coastal surges set to occur once a year by 2100.
“The more we push the climate system … the greater the odds we cross thresholds that we can only poorly project,” said IPCC co-author Bob Kopp, a climate scientist at Rutgers University.
(
Image:
AFP via Getty Images)
Time running out – urgent action needed
Meeting the Paris Agreement goal of limiting warming to 1.5C will require sticking to a “carbon budget,” a term describing how much additional carbon can be pumped into the atmosphere before that goal is likely out of reach.
The world is now on track to use up that budget in about a decade.
With 2.4 trillion tons of climate-warming CO2 added to the atmosphere since the mid-1800s, the average global temperature has risen by 1.1C. That leaves 400 billion tons more that can be added before the carbon budget is blown.
Global emissions currently total a little more than 40 billion tons a year.
Temperatures will continue to rise without drastic cuts
The scientists have drawn up five scenarios for future warming, depending on whether the world continues to burn through fossil fuels.
All five say it is “more likely than not”, at the very least, that the 1.5C threshold will be reached within this time period.
Three of the five scenarios are more pessimistic, estimating that it is “likely”. Under the most optimistic scenario, temperatures are “more likely than not” to come back below 1.5C by the end of the century, with a temporary overshoot of no more than 0.1C. This would require a big cut in emissions.
The report also describes possible futures depending on how dramatically the world cuts emissions. But even the severest of cuts are unlikely to prevent global warming of 1.5 degrees Celsius above pre industrial temperatures.
But without drastic emissions cuts, though, average temperatures could cruise past 2C by the end of the century.
Arctic summers free of ice
Arctic Ocean summer ice will vanish entirely at least once by 2050, under the IPCC’s most optimistic scenario. The region is warming at least twice as fast as the global average.
Arctic sea ice levels vary through the year but the average lows in summer have fallen since the 70s and are now at their lowest levels in a thousand years.
Reflective ice giving way to darker water that absorbs solar radiation, causes even more warming. Big impacts from other tipping points, such as the dieback of forests, could not be ruled out.