Humans are the main culprits of the unprecedented warming rate of the planet for at least 2000 years and many of the changes will be irreversible for centuries to millennia, a landmark UN climate report finds.
The climate is undergoing changes never seen before and human influence is “unequivocal”, according to the latest report by the UN climate panel. After two weeks of heated virtual deliberations between over 100 governments and scientists, the Intergovernmental Panel on Climate Change released on Monday its most alarming report to date.
The highly awaited publication, which drew on over 14,000 studies, is the first of a four-part global assessment of the state of climate change, its impact on humans and the ways in which humans could mitigate those effects by curbing greenhouse gas emissions while protecting themselves from the ones that are unavoidable.
The report “tells us that it is indisputable that human activities are causing climate change,” chair of the IPPC Bureau Hoesung Lee said at the press conference launching the report.
Human fingerprints all over
The fact that climate change was increasing the frequency and severity of extreme weather events, such as floods, hurricanes, droughts, and heat and cold waves, was already recognised in the IPCC’s previous report in 2014. In the latest sobering assessment, the evidence backing such influence is stronger.
Human activities have already caused around 1.1°C of warming since the end of the 19th century, the report says. Over the next two decades, global temperatures are expected to reach or exceed the 1.5°C limit.
Some of the effects, including negative impacts on the ocean, ice sheets and global sea level, will be irreversible for hundreds and even thousands of years to come.
Actions to bring down global emissions, such as moving away from fossil fuels towards cleaner energies, will determine how much the globe continues to heat up.
“If we rapidly reduce greenhouse gas emissions, if we can reach global net zero CO2 emissions around 2050, it is extremely likely that we can keep global warming well below 2ºC,” said Valérie Masson-Delmotte, co-chair of the IPCC working group that produced the document.
“If we do this, it is more likely than not that temperature would gradually decline to below around 1.5ºC by the end of the century, with a temporary overshoot of no more than 0.1ºC,” she added.
Over three decades of warning
The warnings are not new. Scientists have been sounding the alarm for over thirty years that the accelerated rate of warming would have dire consequences for the planet and in turn for humans.
Addressing scientists, UN Environment Programme executive director Inger Andersen said: “You've been telling us for over three decades of the dangers of allowing the planet to warm. The world listened, but didn't hear. The world listened, but it did not act strongly enough and as a result, climate change is a problem that is here now.”
With less than 100 days to go before the climate summit in Glasgow, Andersen urged governments to make net-zero a reality. She also called on them to decarbonise faster, support financially developing countries to adapt to climate change, and restore ecosystems that help draw down carbon and other greenhouse gas emissions.
“Nobody's safe, and it's getting worse faster, we must treat climate change as an immediate threat, just as we must treat the connected crisis of nature and biodiversity loss, and pollution and waste as immediate threats.”