On climate change, work toward the best but plan for the worst

In 2011, a London-based think tank caused a stir at the Pentagon with a different way to think about the risks of global climate change, proposing that countries prepare not for the most likely consequences of global warming but for the worst-case scenarios.

The world hasn’t listened. Despite increasingly dire warnings since the 1950s, governments, corporations, financial markets and consumers are nowhere near confronting the extraordinary threats climate change poses to social and economic security.

Instead, the fossil-energy industry and oil-igarchs have imposed their will on the policies of most governments. At last count, governments and markets are expected to subsidize fossil fuels with more than $8 trillion by 2030, which is a lot like addressing addiction by paying drug dealers to lower their prices. 

Under President Trump, the U.S. has become the poster child of this perverse practice — not only as the oil industry’s biggest booster, but also by suppressing the growth of clean energy. During his 2024 campaign, Trump was caught telling oil executives he would give them the keys to the kingdom if they gave him millions of dollars. 

And indeed, Trump has traded America’s energy security for the oil industry’s generous donations to his election campaign, inaugural festivities and construction of his White House ballroom. Trump dismisses that global warming itself has already emasculated the government’s ability to anticipate and mitigate warming’s dystopian risks, and he is trying to shut down state policies, too. 

As a result, the worst case today is considerably worse than it was in 2011, and it will keep getting worse until we do something about it.

What should that be?  Given the gaps in our knowledge about how the Earth operates, the uncertainties of nonexistent technical fixes, the economy’s inertia, the pushback by vested interests, and the perennial problem of short-term leaders changing our energy policies to suit ideologies rather than sound science, the prudent course is to manage against the direst scenarios that reputable science identifies. 

The Paris climate agreement says that to avoid catastrophe, the world must keep warming well below 2 degrees Celsius above pre-industrial levels. (Many scientists believe the preferred Paris target of 1.5 degrees is no longer possible.)  However, most developed countries are not meeting their own commitments to reduce pollution. The United Nations Environment Program (UNEP) estimates that current plans will result in 2.8 degrees of warming. Some anticipate warming of 4.0 degrees — more than six feet of sea-level rise, making entire regions uninhabitable.

The UNEP says that Trump’s inaction alone will result in an additional tenth of a degree warming. While tenths may seem insignificant, the U.N. points out that “Every 0.1°C exacerbates drought, heatwaves, and flood intensity, meaning smaller fractions are crucial for tipping points and irreversible damages.”

These estimates are for Earth’s average temperature; actual warming could be twice as high in some locations. A new study in Nature reiterates what that London think tank, E3G, advised 15 years ago: To protect the world’s food security and ecosystem functions, “effective policy should take into account worst-case scenarios as well as average projections.”

The warning signs could not be clearer. The emissions that cause global warming reached a record high last year. The blanket of pollution in the atmosphere, which traps the sun’s heat at Earth’s surface, keeps getting thicker (now approaching nearly 430 parts per million and rising rapidly, compared to the safe level of 350 ppm). The concentration is higher than it has been in 2 million years. The last 11 years have been the hottest on record. Global warming is accelerating nearly twice as fast today as it did in 2015. 

Right now, the world’s response is to hope that we can adapt to higher temperatures, and that “innovation” will fix things, such as altering the behavior of sunlight and oceans rather than society’s energy habits. But back in 2011, the Pentagon seemed to take E3G’s advice to heart, and subsequent national security reviews took climate risks more seriously. Sadly, when Trump became president in 2017, climate change disappeared from U.S. security strategy.   

Americans have different views on many things, but there is one on which tens of millions of us apparently agree. This is a terrible time to have climate-change deniers in government. In fact, the International Court of Justice ruled last year that countries “have a clear legal obligation under international law to … prevent greenhouse gas emissions from causing significant harm.”  In other words, the unholy alliance between governments and big oil should be illegal. 

Gallup says 44 percent of Americans, the highest in nearly 40 years, worry a great deal about climate change. There are many reasons to revolt against the federal government’s regressive policies today. The enormous threat to the quality of our lives, and our children’s, is certainly one. 

William Becker is executive director of the Presidential Climate Action Project and a former senior official at the U.S. Department of Energy. He worked with E3G in 2011 but is not affiliated with it today.