Tuesday, March 1, 2022

A climate science update: A bit of good news

One of the biggest obstacles to avoiding global climate breakdown is that so many people think there’s nothing we can do about it.[1]

.... the best climate science you’ve probably never heard of suggests that humanity can still limit the damage to a fraction of the worst projections if — and, we admit, this is a big if — governments, businesses and all of us take strong action starting now.

For many years, the scientific rule of thumb was that a sizable amount of temperature rise was locked into the Earth’s climate system. Scientists believed — and told policymakers and journalists, who in turn told the public — that even if humanity hypothetically halted all heat-trapping emissions overnight, carbon dioxide’s long lifetime in the atmosphere, combined with the sluggish thermal properties of the oceans, would nevertheless keep global temperatures rising for 30 to 40 more years. Since shifting to a zero-carbon global economy would take at least a decade or two, temperatures were bound to keep rising for at least another half-century.

But guided by subsequent research, scientists dramatically revised that lag time estimate down to as little as three to five years. That is an enormous difference that carries paradigm-shifting and broadly hopeful implications for how people, especially young people, think and feel about the climate emergency and how societies can respond to it.

This revised science means that if humanity slashes emissions to zero, global temperatures will stop rising almost immediately. To be clear, this is not a get-out-of-jail-free card. Global temperatures also will not fall if emissions go to zero, so the planet’s ice will keep melting and sea levels will keep rising. But global temperatures will stop their relentless climb, buying humanity time to devise ways to deal with such unavoidable impacts. In short, we are not irrevocably doomed — or at least we don’t have to be, if we take bold, rapid action.  
Nonscientists can reasonably ask: What made scientists change their minds? Why should we believe their new estimate of a three-to-five-year lag time if their previous estimate of 30 to 40 years is now known to be incorrect? And does the world still have to cut emissions in half by 2030 to avoid climate catastrophe?

The short answer to the last question is yes. Remember, temperatures only stop rising once global emissions fall to zero. Currently, emissions are not falling. Instead, humanity continues to pump approximately 36 billion tons of carbon dioxide a year into the atmosphere. The longer it takes to cut those 36 billion tons to zero, the more temperature rise humanity eventually will face. And as the IPCC’s 2018 report made hauntingly clear, warming of more than 1.5 degrees Celsius would cause unspeakable amounts of human suffering, economic loss and social breakdown — and perhaps trigger genuinely irreversible impacts.  
Knowing that 30 more years of rising temperatures are not necessarily locked in can be a game-changer for how people, governments and businesses respond to the climate crisis. Understanding that we can still save our civilization if we take strong, fast action can banish the despair that paralyzes people and instead motivate them to get involved. Lifestyle changes can help, but that involvement must also include political engagement. Slashing emissions in half by 2030 demands the fastest possible transition away from today’s fossil-fueled economies in favor of wind, solar and other non-carbon alternatives.[2] That can happen only if governments enact dramatically different policies. If citizens understand that things aren’t hopeless, they can better push elected officials to make such changes. (emphasis added)


Footnote: 
1. The other biggest obstacle to avoiding adverse global climate changes is a toxic combination of the American Republican Party, a big slice of the American business community, e.g., the energy and chemical sectors, capitalist ideologues, crackpot climate science deniers and crackpot conspiracy theorists and decades of anti-climate science propaganda and lies that have successfully blocked most serious meaningful action.  

2. "Other non-carbon alternatives" include nuclear power (and maybe geothermal power). Each time the press fails or refuses to say or write the words "nuclear power" is a major mistake. It's an opportunity that cannot be recovered. It leaves the possibility out of the public's mind. Because it is failing on climate change reporting, the MSM gets a well-deserved grade of F. 

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