The past decade has seen an astonishing run of record-breaking storms, forest fires, droughts, coral bleaching, heat waves, and floods around the world with just 1.8 degrees Fahrenheit (1.0 degrees Celsius) of global warming. [See: Hidden Costs of Climate Change Running Hundreds of Billions a Year] But much of this will get substantially worse with 2.7 degrees Fahrenheit of warming, and far worse at 3.6 degrees Fahrenheit (2 degrees Celsius), according to the IPCC’s “Special Report on Global Warming of 1.5°C”, released Sunday and examining more than 6,000 studies.
The IPCC also reported that 2.7 degrees Fahrenheit could be reached in as little as 11 years—and almost certainly within 20 years without major cuts in carbon dioxide (CO2) emissions. Even if such cuts were to begin immediately it would only delay, not prevent, 2.7 degrees Fahrenheit of global warming.
While a 0.9 degrees Fahrenheit (0.5 degrees Celsius) increase in room temperature is unnoticeable, permanently heating the whole planet that much will have “substantial” consequences, the report warns. The impacts will be felt across ecosystems and human communities and economies. Canoes are vital for transportation on the rainforest rivers of the Republic of the Congo. The Congo Basin’s 500 million acres of tropical forest, second-largest in the world after the
“Limiting global warming to 1.5°C compared with 2°C would reduce challenging impacts on ecosystems, human health, and well-being,” said Priyardarshi Shukla, Chair of the Global Centre for Environment and Energy at Ahmedabad University in India and co-author of the Special Report, in a statement. Such impacts include stronger storms, more erratic weather, dangerous heat waves, rising seas, and large-scale disruption to infrastructure and migration patterns.
Climate change impacts worse than expected, the global report warns
The scientific findings in the main report are summarized in a 34-page “Summary for Policy Makers,” which was approved by all representatives from 195 nations, including the U.S.
Under the 2015 Paris Agreement, every country in the world agreed to keep global temperatures well below 3.6 degrees Fahrenheit (2 degrees Celsius), while low-lying island states and others lobbied for substantially less. Current pledges to cut CO2 emissions will push global warming to at least 5.4 degrees Fahrenheit (3 degrees Celsius) by 2100, risking natural tipping points such as thawing of large areas of permafrost—which could drive global temperatures uncontrollably higher. The Trump administration has said they will pull the U.S. out of the Paris Agreement.
Global warming is like being in a minefield that gets progressively more dangerous, says Michael Mann, a climatologist, and director of the Earth System Science Center at Penn State. “The further we go the more explosions we are likely to set off: 1.5C is safer than 2C, 2C is safer than 2.5C, 2.5C is safer than 3C, and so on,” said Mann, who was not directly involved in this latest IPCC report.
“Stabilizing global warming at 1.5C will be extremely difficult if not impossible at this point,” Mann said via email.