HOUSTON — Earth is getting so hot that temperatures in about a decade will probably blow past a level of warming that world leaders have sought to prevent, according to a report released Monday that the United Nations called a “code red for humanity.”
Note: the video in this story is from an Aug. 4 broadcast — "Hurricane Harvey’s impact still evident in many areas nearly four years after flood"
“It’s just guaranteed that it’s going to get worse,” said report co-author Linda Mearns, a senior climate scientist at the U.S. National Center for Atmospheric Research. “Nowhere to run, nowhere to hide.”
Once-in-a-decade storms becoming more common
Heavy precipitation will become more frequent and more intense with every degree of warming, the report concludes, because warmer air can hold more water, simply put.
CNN points out that Hurricane Harvey dumped more than 60 inches of rain on some parts of the Houston area in 2017. This prompted the National Weather Service to add two colors to the scale on its precipitation maps — purple for 20-30 inches, and pink for more then 30 inches.
"Storms like Hurricane Harvey, which hit Texas in 2017, and Hurricane Lane which drenched Hawaii in 2018, not only slam coasts with storm surge and damaging winds, but also cause more intense inland deluges because of global warming," reported CNN.
Houston Mayor Sylvester Turner, who is the Chair of Climate Mayors, tweeted this message in response to Monday's report.
As the global temperature rises, extreme precipitation events will drop more water and hurricanes will worsen, warns the report.
But scientists also eased back a bit on the likelihood of the absolute worst climate catastrophes.
Multiple climate disasters at once
As the planet warms, places will get hit more not just by extreme weather but by multiple climate disasters at once, the report said. That’s like what’s now happening in the Western U.S., where heat waves, drought and wildfires compound the damage, Mearns said. Extreme heat is also driving massive fires in Greece and Turkey.
Some harm from climate change — dwindling ice sheets, rising sea levels and changes in the oceans as they lose oxygen and become more acidic — is “irreversible for centuries to millennia,” the report said.
The world is “locked in” to 15 to 30 centimeters (6 to 12 inches) of sea level rise by mid-century, said report co-author Bob Kopp of Rutgers University.
Scientists have issued this message for more than three decades, but the world hasn't listened, said United Nations Environment Program Executive Director Inger Andersen.
For the first time, the report offers an interactive atlas for people to see what has happened and may happen to where they live.
Nearly all of the warming that has happened on Earth can be blamed on emissions of heat-trapping gases such as carbon dioxide and methane. At most, natural forces or simple randomness can explain one- or two-tenths of a degree of warming, the report said.
The report described five different future scenarios based on how much the world reduces carbon emissions. They are: a future with incredibly large and quick pollution cuts; another with intense pollution cuts but not quite as massive; a scenario with moderate emission cuts; a fourth scenario where current plans to make small pollution reductions continue; and a fifth possible future involving continued increases in carbon pollution.
In five previous reports, the world was on that final hottest path, often nicknamed “business as usual.” But this time, the world is somewhere between the moderate path and the small pollution reductions scenario because of progress to curb climate change, said report co-author Claudia Tebaldi, a scientist at the U.S. Pacific Northwest National Lab.
Houston's role
Human habits, if left unchanged, could lead to even more unpredictability, Houston energy expert Ed Hirs warns.
“The variability of the weather patterns is going to increase such that we’re likely to see more extremes in addition to just a warmer overall environment," Hirs said.
As the energy capital of the world, he says Houston is in a unique position to lead in change.
“We are taking the lead in the transition in renewable energy sources.”
Examples include solar, wind and renewable fuels from biofeed stocks -- which could all be essential in changing where and how we get energy.
Carbon emissions scenarios
Monday's authoritative Intergovernmental Panel on Climate Change (IPCC) report, which calls climate change clearly human-caused and “unequivocal,” makes more precise and warmer forecasts for the 21st century than it did last time it was issued in 2013.
Each of five scenarios for the future, based on how much carbon emissions are cut, passes the more stringent of two thresholds set in the 2015 Paris climate agreement. World leaders agreed then to try to limit warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above levels in the late 19th century because problems mount quickly after that. The world has already warmed nearly 1.1 degrees Celsius (2 degrees Fahrenheit) since then.
Under each scenario, the report said, the world will cross the 1.5-degree-Celsius warming mark in the 2030s, earlier than some past predictions. Warming has ramped up in recent years, data shows.
“Our report shows that we need to be prepared for going into that level of warming in the coming decades. But we can avoid further levels of warming by acting on greenhouse gas emissions,” said report co-chair Valerie Masson-Delmotte, a climate scientist at France’s Laboratory of Climate and Environment Sciences at the University of Paris-Saclay.
In three scenarios, the world will also likely exceed 2 degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial times — the less stringent Paris goal — with far worse heat waves, droughts and flood-inducing downpours unless there are deep emissions cuts, the report said.
“This report tells us that recent changes in the climate are widespread, rapid and intensifying, unprecedented in thousands of years,” said IPCC Vice Chair Ko Barrett, senior climate adviser for the U.S. National Oceanic and Atmospheric Administration.
With crucial international climate negotiations coming up in Scotland in November, world leaders said the report is causing them to try harder to cut carbon pollution. U.S. Secretary of State Anthony Blinken called it “a stark reminder."
The 3,000-plus-page report from 234 scientists said warming is already accelerating sea level rise and worsening extremes such as heat waves, droughts, floods and storms. Tropical cyclones are getting stronger and wetter, while Arctic sea ice is dwindling in the summer and permafrost is thawing. All of these trends will get worse, the report said.
For example, the kind of heat wave that used to happen only once every 50 years now happens once a decade, and if the world warms another degree Celsius (1.8 degrees Fahrenheit), it will happen twice every seven years, the report said.
SETH BORENSTEIN (AP Science Writer) contributed to the bulk of this report
CNN contributed to this report