Climate change: First IPCC report since 2013 projects major global shifts

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FILE – In this Thursday, July 1, 2021 file photo, a wildfire burns in the mountains north of Lytton, British Columbia, Canada, during record high temperatures. According to a study released on Wednesday, July 7, 2021, the deadly heat wave that roasted the Pacific Northwest and western Canada “was virtually impossible without human-caused climate change” which also added a few extra degrees to the record-smashing warmth. (Darryl Dyck/The Canadian Press via AP, File)

(KXAN) — For the first time since 2013, the Intergovernmental Panel on Climate Change (IPCC) has released its latest assessment report on the impact of climate change on Earth.

In addition to new information on how the global climate has changed, the IPCC provides details on physical science, study on impacts of the science and the mitigation of their findings. These findings aren’t meant to force policy change, but they are intended to provide guidance for what needs to be done if policymakers want to make changes.

The reports, which are not researched by IPCC, are drafted and reviewed in several stages for objectivity and transparency.

Assessments are released in three different reports. The first was released Monday and outlines five different scenarios of what would happen if global CO2 emissions were to cease at different timelines through 2100. The second and third reports are expected in 2022 and will explore what can be done to adapt to these changes and how worst-case scenarios can be prevented.

Findings from the last update back in 2013 helped initiate the Paris Climate Accord.

Here are five key takeaways, according to

1. Surface warming to skyrocket by 2040

Drastic warming has been under way across the world over the last century at historic rates. This increase in temperatures has reduced options for reducing our 1.5C temperature rise since before the industrial revolution by quite a bit.

Under all emissions scenarios outlined in the IPCC report, Earth’s surface warming is projected to reach 1.5C or 1.6C in the next two decades. New model data, that was not used in any of the previous reports, indicate the timeline for meeting this threshold is shrinking mainly due to high global emissions that have only continued to climb in the past eight years.

2. Human influence on the climate

While AR5 concluded that human influence on the climate system is “clear,” AR6 said there is “high confidence” that human activities are the main drivers of more frequent or intense occurrences like heatwaves, glacial melting, ocean warming and acidification. 

Thanks to advanced computer modeling, scientists can now determine how likely specific weather events are to happen — with and without current climate change information.

Events like the Pacific Northwest heatwave and Texas winter storms are a few examples that were highly unlikely without the impacts of a warming world.

“It is unequivocal that human influence has warmed the atmosphere, ocean and land,” the report concludes. 

3. Projecting what could happen and where

Scientists can now analyze current and projected extremes on regional levels and understand what global climate impacts will look like in different parts of the world. 

New modelling indicates that areas near the Arctic poles are warming at an alarming rate compared to areas near the equator. This is likely because temperatures don’t vary nearly as much as they do in the poles. Models also indicate the Gulf Stream will weaken, cutting off the warm conveyor belt of storms that keep much of Europe in a moderate climate.

“The climate models have improved since the last report, they have higher spatial resolution which allows you to see more regional impacts and they are better at simulating what will happen in the future in specific regions,” Stephen Cornelius, the IPCC lead for WWF, told Climate Home News.

4. Irreversible tipping points 

It’s even more likely now that we’ve reached irreversible changes, also known as “tipping points.”

This could result in forests dying off because of blistering temperatures, centuries-old ice sheets melting, and some drier areas actually becoming full deserts.

“The probability of low-likelihood, high impact outcomes increases with higher global warming levels,” the report notes. “Abrupt responses and tipping points of the climate system, such as strongly increased Antarctic ice sheet melt and forest dieback, cannot be ruled out.” 

Recent studies have shown that U.S. coastlines are seeing more high-tide flooding than ever before, likely due to the rapid melting of the polar icecaps exacerbating the natural high tides.

“We are now observing climate change with our own eyes in ways we did not do so before. Many temperature extremes are outside the bounds of natural variability and triggering extreme events, such as wildfires,” said Corinne Le Quere, a climate scientist at the University of East Anglia, at a briefing last month.

5. Methane emissions are an important lever

Methane levels are higher than at any point in the past 800,000 years and are well above the safe limits outlined in AR5. 

Methane is released by abandoned coal mines, farming and oil and gas operations — it’s responsible for almost a quarter of global warming. All-in-all methane has a global warming impact 84 times higher than CO2 over a 20-year period.

For the first time ever, the IPCC now has an entire chapter of their report dedicated to methane emissions.

Ecosystem responses to global warming, such as thawing permafrost and wildfires, are highly likely to further increase concentrations of methane in the atmosphere. The authors state that a strong and rapid reduction in methane emissions would not only curb global warming but also improve air quality.

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