Quanta Magazine: “…For centuries, humans have sought to understand the intricate workings of our planet. As vulnerable critters, we crave some control over nature, or at least a handle on coming shifts in the weather and climate. But Earth is a chaotic beast, sensitive to innumerable tiny details; we can’t possibly keep track of every speck of dust. Therein lies the challenge of climate modeling: building a computer model of Earth’s surface and atmosphere that captures the gist of its behavior simply but effectively. “The goal of climate modeling is really to build a fake version of the Earth,” said Isla Simpson (opens a new tab), an atmospheric scientist at the National Center for Atmospheric Research — a coarse-grained copy of the planet that’s stripped down to “the processes we think are relevant.” Over the past 60 years, this effort has come to fruition. Generations of scientists have dedicated their careers to sculpting increasingly sophisticated planetary replicas. Computer models of Earth have helped us reconstruct past epochs, forecast long-term weather trends and, above all, understand how human activities are changing the climate. From the very first computer simulations, climate models have shown that carbon dioxide released by the burning of fossil fuels warms the planet considerably. In the decades since, more advanced simulations show how a warming planet could trigger all sorts of calamities, from heat waves and superstorms to desertification and ecosystem collapse. According to modeling results compiled by the United Nations (opens a new tab), Earth is on track to warm between 2.6 and 3.1 degrees Celsius over the course of this century. The last time Earth was that warm was around 3 million years ago (opens a new tab) during the Pliocene era, when fires ravaged the Arctic (opens a new tab) and sea levels were some 50 feet higher than they are today.

As the frightening futures foretold grow nearer, the details are also growing more precise. Climate scientists have reached a pivotal moment in which their predictions are being borne out, allowing them to recalibrate and hone their models. “We were essentially predicting worlds we couldn’t see for a very long time,” said Tiffany Shaw (opens a new tab), a climate dynamicist and geophysicist at the University of Chicago. Watching the ramifications of climate change play out in the real world has both validated the models and highlighted their shortcomings. Now, modelers are exploring new approaches that could usher in the next generation of fine-grained models that make better regional predictions. As climate modeling enters this critical phase of refinement, the effort faces its greatest challenge yet. Since taking office, the Trump administration has taken siege to the U.S. research ecosystem, with a particular focus on undermining the quest to track Earth’s climate. Decades of work is on the line as the administration strips (opens a new tab) funding, guts (opens a new tab) agencies, scrubs (opens a new tab) resources and buries (opens a new tab) datasets. “It’s a whole-scale destruction and not something that will be undone,” said Bjorn Stevens (opens a new tab), a climate scientist and the director of the Max Planck Institute for Meteorology in Germany. “It’s a completely existential threat.”…

See also The New York Times – It Isn’t Just the U.S. The Whole World Has Soured on Climate Politics. “How do we think about the climate future, now that the era marked by the Paris Agreement has so utterly disappeared?…The most conspicuous retreat, of course, has been the United States under President Trump, who first announced his intention to withdraw from Paris way back in 2017 with a ceremony in the Rose Garden. Trump has celebrated his return to office by utterly dismantling his predecessor’s signature climate bill, the Inflation Reduction Act, and vowing to stop all approvals for new renewable projects (not to mention paving over that same garden). But this is not just a story about Trump. When Paris was forged, the United States was a trivial exporter of natural gas, and it was still illegal to ship American oil abroad. Even before Trump’s second inauguration, the country had become the world’s largest producer and exporter of refined oil and liquid natural gas…”