UN report: Effects of climate change even more severe than we thought

Global warming is happening so fast that scientists now say we’ll cross a crucial temperature threshold as early as 2030 — up to a decade sooner than previously thought — according to a sweeping new UN-sponsored review of climate science published Monday.

The big picture: Atmospheric CO2 concentrations were higher in 2019 than at any time in at least 2 million years, and the past 50 years saw the fastest temperature increases in at least 2,000 years, according to the new assessment by the Intergovernmental Panel on Climate Change (IPCC).

What they’re saying: The report says that the connection between human emissions of greenhouse gases and global warming is “unequivocal.”

  • It’s the “strongest statement the IPCC has ever made,” Ko Barrett, the panel’s vice chair and senior advisor on climate to the National Oceanic and Atmospheric Administration, told reporters.

Why it matters: Warming is affecting every area of the globe, making the world a more volatile place, and the report connects the dots between extreme events and long-term human causes.

  • Weather and climate events are becoming more common and severe, it says, and rising sea levels are flooding coastal areas with regularity.
  • It shows we’re running out of time to meet the targets of the Paris Climate Agreement.

Details: The IPCC looked at how long it will take the world to reach a temperature warming target of 1.5°C (2.7°F) compared to preindustrial levels and determined that could happen between 2030 and 2035.

  • The 20-year period from now through 2040 will be the first to meet or beat that target, the panel found.
  • Even under the lowest pathway of future greenhouse gas emissions, the 1.5-degree threshold would be exceeded for a period of time.

Only rapid, steep and sustained greenhouse gas emissions cuts, down to net zero and eventually net negative values, could avoid exceeding 1.5 or 2°C (3.6°F) of warming over the longer-term, the report states. The world has already warmed by 1.1°C (2°F) relative to the 1850-1900 average.

  • The report also notes that many of the effects of climate change through 2050 are already locked in by the emissions to date, but there is still time to greatly reduce climate impacts later this century.

Yes, but: The world is nowhere near making the emissions cuts in line with the Paris Agreement targets, instead tracking toward at least 3°C (5.4°F) of warming, based on the latest emissions reduction pledges.

Between the lines: The peer-reviewed report, conducted by hundreds of authors around the world, arrives at a hinge point in the global fight against climate change.

  • Leaders in the U.S. and European Union are seeking to enact strict new measures to cut greenhouse gas emissions and keep the 1.5-degree goal alive, with a pivotal summit slated for November in Glasgow. But consensus on emissions cuts among all of the wealthiest nations remains elusive.
  • It also comes amid an outbreak of extreme weather events that have killed hundreds in the Pacific Northwest in a scorching heat wave, with devastating wildfires striking the U.S., Canada, Russia and the Mediterranean region this summer.
  • The report touches on tipping points in the climate system, such as the shutdown of the Gulf Stream and collapse of part of the Antarctic Ice Sheet, categorizing them as low-risk but high-impact events.

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World leaders, activists react to “sobering” UN climate report

A sweeping United Nations-sponsored review of climate science published Monday projected that the world will cross a crucial temperature threshold as early as 2030 — up to a decade sooner than previously thought.

Why it matters: Warming is affecting every area of the globe, the report notes, and extreme weather events are becoming more common and severe contributing to a more volatile world.

What they’re saying:

United Kingdom: “Today’s report makes for sobering reading, and it is clear that the next decade is going to be pivotal to securing the future of our planet. We know what must be done to limit global warming – consign coal to history and shift to clean energy sources, protect nature and provide climate finance for countries on the frontline,” U.K. Prime Minister Boris Johnson said in a statement.

  • The U.K. hosts the 2021 United Nations Climate Change Conference, also known as the COP26 summit, in November.

United States: “The IPCC report underscores the overwhelming urgency of this moment. The world must come together before the ability to limit global warming to 1.5 degrees Celsius is out of reach,” U.S. special climate envoy John Kerry said in a statement.

  • “As the IPCC makes plain, the impacts of the climate crisis, from extreme heat to wildfires to intense rainfall and flooding, will only continue to intensify unless we choose another course for ourselves and generations to come.”
  • Secretary of State Antony Blinken added in his own statement: “We cannot delay ambitious climate action any longer.”
  • Eric Lander, President Biden’s science advisor, said the report confirms “that climate change is intensifying faster than we thought.”

Activists: “The new IPCC report contains no real surprises. It confirms what we already know from thousands previous studies and reports – that we are in an emergency. It’s a solid (but cautious) summary of the current best available science,” Greta Thunberg tweeted.

  • “Today, I, and so many other young people, wake up enraged — the IPCC report is apocalyptic, catastrophic, and nothing we haven’t been screaming from the rooftops for years. Our politicians shouldn’t need a report to tell them how bad things are. We’re already living it,” Varshini Prakash, executive director of the Sunrise Movement, said in a statement.

This story will be updated with more reactions.

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