‘THIS IS THE LAST CHANCE TO GET THINGS RIGHT’ ON GLOBAL WARMING
CONICET’S CAROLINA VERA ON THE NEW IPCC CLIMATE CHANGE REPORT
Preventing an extra half-degree Celsius of heat could make a life-or-death difference in the next few decades for multitudes of people and ecosystems on this fastwarming planet, an international panel of scientists put together by the Unitd Nations reported this week.
However, the report’s authors provide little hope the world will rise to the challenge, warning that while such a goal is feasible on paper, it would require political will and vast economic transformations that are not on the near-term horizon.
The Nobel Prize-winning Intergovernmental Panel on Climate Change (IPCC) issued its gloomy report at a meeting in Incheon, South Korea, on Monday. In the 728-page document, the United Nations organisation detailed how Earth’s weather, health and ecosystems would be in better shape if the world’s leaders could somehow limit future human-caused warming to just a half-degree Celsius (0.9 degrees Fahrenheit) from now, instead of the globally agreed-upon goal of 1ºC.
The special report on global warming of 1.5ºC above preindustrial levels began as a request from the 195 nations that inked the Paris Agreement in 2015. That landmark pact called for capping the rise in global temperature to “wellbelow” 2ºC, and invited countries to submit voluntary national plans for reducing greenhouse gas emissions.
To the surprise of many – especially scientists, who had based nearly a decade of research on the assumption that 2ºC was the politically acceptable guardrail for a climate-safe world – the treaty also called for a good-faith effort to cap warming at the lower threshold.
At the same time, countries asked the IPCC to detail what a 1.5ºC world would look like, and how hard it might be to prevent a further rise in temperature.
“Unfortunately, we are already well on the way to the 1.5ºC limit, and the sustained warming trend shows no sign of relenting,” Elena Manaenkova, Deputy Secretary-General of the World Meteorological Organisation said this week.
Three years and many drafts later, the answer has come in the form of a 400-page report – grounded in an assessment of 6,000 peer-reviewed studies – that delivers a stark, double-barrelled message: 1.5ºC is enough to unleash climate mayhem, and the pathways to avoiding an even hotter world require a swift and complete transformation not just of the global economy, but of society too.
With only 1ºC of warming so far, the world has seen a climate-enhanced crescendo of deadly heatwaves, wild fires and floods, along with superstorms swollen by rising seas.
“I don’t know how you can possibly read this and find it anything other than wildly alarming,” said Peter Frumhoff, director of science and policy at the Union of Concerned Scientists, a Washington-based research and advocacy group, referring to the draft “Summary for policymakers.”
A QUESTION OF AMBITION
“For some people this is a life-or-death situation without a doubt,” said Cornell University climate scientist Natalie Mahowald, a lead author on the report.
Limiting warming to 0.5°C from now means the world can keep “a semblance” of the ecosystems we have. Adding another 0.5°C degrees on top of that — the looser global goal — essentially means a different and more challenging Earth for people and species, said another of the report’s lead authors, Ove Hoegh-Guldberg, director of the Global Change Institute at the University of Queensland, Australia.
But meeting the more ambitious goal of slightly less warming would require immediate, draconian cuts in emissions of heat-trapping gases and dramatic changes in the energy field. While the UN panel says technically that’s possible, it saw little chance of the needed adjustments happening.
In 2010, international negotiators adopted a goal of limiting warming to 2°C since pre-industrial times. It’s called the ‘two-degree goal.’ In 2015, when the nations of the world agreed to the historic Paris climate agreement, they set dual goals: 2°C and a more demanding target of 1.5°C from pre-industrial times. The 1.5°C was at the urging of vulnerable countries that called 2°C degrees a death sentence.
The world has already warmed 1°C since pre-industrial times, so the talk is really about the difference of another 0.5°C or 0.9°F from now.
“There is no definitive way to limit global temperature rise to 1.5°C above pre-industrial levels,” the UN-requested report said. More than 90 scientists wrote the report, which is based on more than 6,000 peer reviews.
“Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate,” the report states.
Deep in the report, scientists say less than two percent of 529 of their calculated possible future scenarios kept warming below the 1.5°C goal without the temperature going above that and somehow coming back down in the future.
The pledges nations made in the Paris agreement in 2015 are “clearly insufficient to limit warming to 1.5°C in any way,” one of the study’s lead authors, Joerj Roeglj of the Imperial College in London, said.
“I just don’t see the possibility of doing the one and a half” and even 2°C looks unlikely, said Appalachian State University environmental scientist Gregg Marland, who isn’t part of the UN panel but has tracked global emissions for decades for the US Energy Department.
He likened the report to an academic exercise wondering what would happen if a frog had wings.
‘UNPRECEDENTED CHANGES’
Some of the authors said they remained optimistic.
Limiting warming to the lower goal is “not impossible but will require unprecedented changes,” UN panel chief Hoesung Lee said in a press conference in which scientists repeatedly declined to spell out just how feasible that goal is. They said it is up to governments to decide whether those unprecedented changes are acted upon.
“We have a monumental task in front of us, but it is not impossible,” Mahowald said. “This is our chance to decide what the world is going to look like.”
To limit warming to the lower temperature goal, the world needs “rapid and far-reaching” changes in energy systems, land use, city and industrial design, transportation and building use, the report said. Annual carbon dioxide pollution levels that are still rising now would have to drop by about half by 2030 and then be near zero by 2050. Emissions of other greenhouse gases, such as methane, also will have to drop. Switching away rapidly from fossil fuels like coal, oil and gas to do this could be more expensive than the less ambitious goal, but it would clean the air of other pollutants. That would have the side benefit of avoiding more than 100 million premature deaths this century, the report said.
“Climate-related risks to health, livelihoods, food security, water supply, human security and economic growth are projected to increase with global warming” the report said, adding the world’s poor are more likely to get hit hardest.
Princeton University climate scientist Michael Oppenheimer said extreme weather, especially heat waves, will be deadlier if the lower goal is passed.
Meeting the tougher-to-reach goal “could result in around 420 million fewer people being frequently exposed to extreme heat waves, and about 65 million fewer people being exposed to exceptional heat waves,” the report said. The deadly heat waves that hit India and Pakistan in 2015 will become practically yearly events if the world reaches the hotter of the two goals, the report said.
Coral and other ecosystems are also at risk. The report said warmer water coral reefs “will largely disappear.”
The question now is if the report will spur governments and people to act quickly and strongly, said one of the panel’s leaders, German biologist Hans-Otto Portner. “If action is not taken, it will take the planet into an unprecedented climate future.”
The pledges nations made in the Paris agreement in 2015 are “clearly insufficient,” one of the study’s lead authors said.