UN climate change report is a ‘reality check’ — and that reality is grim
Climate strike at the Michigan Capitol, Sept. 20, 2019 | Laina G. Stebbins
The numerical difference between 1.5 degrees and 2 degrees Celsius is small, but it stands between all that is alive and a potentially cataclysmic capsizing of the natural world.
As soon as 2030 — a decade earlier than previously estimated —the Earth’s average temperature is on track to rise by 1.5 degrees Celsius over pre-industrial times, if warming continues to increase at the current rate, according to a voluminous report published Monday by scientists on the United Nations’ Intergovernmental Panel on Climate Change (IPCC).
Today, the planet is already 1 degree Celsius warmer.
If we fail to rein in greenhouse gases, like carbon dioxide, methane and nitrous oxide, then a 2-degree Celsius increase is likely within the next 30 years. That would accelerate a chain of events that’s already begun: thawing permafrost, extreme weather, such as floods, wildfires and prolonged droughts, sea level rise, melting ice sheets, loss of wildlife habitat.
“This report is a reality check,” said IPCC Working Group I Co-Chair Valérie Masson-Delmotte in a press release. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”
For humans, whose health and viability is intricately linked to that of the global ecosystems, this is an existential threat. Deaths related to heat, flooding and pollution; insect-borne diseases, food shortages, losses of homes and livelihoods, while occurring now would only get worse.
But even the almost-certain increase of 1.5 degrees Celsius carries significant risks. “Warming of 1.5°C is not considered ‘safe’ for most nations, communities, ecosystems and sectors and poses significant risks to natural and human systems,” the report said.
The most vulnerable global communities are the poor, the underserved and the marginalized, both in the U.S. and abroad.
Warming from human-made emissions “will persist for centuries to millennia and will continue to cause further long-term changes in the climate system, such as sea level rise, with associated impacts.”
IPCC scientists have “medium confidence” in the projection that of 105,000 species studied, 6% of insects, 8% of plants and 4% of vertebrates would lose over half of their climatically determined geographic range for global warming of 1.5°C.”
At 2 degrees, 18% of insects, 16% of plants and 8% of vertebrates would lose their habitats, and either have to migrate and adapt or perish.
The primary way to slow down the pace of climate change is through sweeping policies about land use, including agriculture; transportation and energy sources. The IPCC report recommends “deep reductions not only of carbon dioxide, but also methane and black carbon” — soot — by more than a third by 2050, compared to 2010 levels.
Natural gas, according to the IPCC report releases methane into the atmosphere, primarily at fracked gas wellheads and through pipeline leaks.
The IPCC report says that to limit warming to 1.5 degrees Celsius above pre-industrial levels, the planet must not only reach net-zero carbon dioxide emissions, but also “concurrent deep reductions” in non-carbon dioxide greenhouse gases, “particularly methane.”
“Though CO2 dominates long-term warming, the reduction of warming short-lived climate forcers, such as methane and black carbon, can in the short term contribute significantly to limiting warming to 1.5°C. … Reductions of black carbon and methane would have substantial co-benefits, including improved health due to reduced air pollution.”
Methane emissions can be reduced “as a result of broad mitigation measures in the energy sector,” the report concludes, including decreases of the potent greenhouse gas from agriculture and landfills.
“Improved air quality resulting from these reductions provide direct and immediate health benefits,” the report said.
Unless greenhouse gas reductions are quick, ambitious and sustained, it will be “exceedingly difficult, if not impossible” to stay under the 1.5 degree Celsius benchmark, the report said. “Limiting warming to 1.5°C would require all countries and non-state actors to strengthen their contributions without delay.”
A version of this story first ran in the Advance‘s sister outlet, NC Policy Watch. Read the story here.
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