This story originally appeared on Reveal and is part of the Climate Desk collaboration.

Next month, a Silicon Valley engineer plans to head out on a snowmobile from Barrow, on the northern tip of Alaska, to sprinkle reflective sand on a frozen lake to try to stop it from melting.

It’s part of a journey that began in 2006, after Leslie Field watched the climate change documentary “An Inconvenient Truth” and felt like she’d been “hit by a big fat truck.” Now, she hopes to gather global support to cover more than 19,000 square miles of sea ice—an area about the size of Costa Rica—with a thin coating of tiny floating silica spheres, which she claims will help reduce the world’s rising temperatures.

The cost estimate? $1 billion a year.

“I keep thinking, ‘If not me, who?’” Field, a former researcher at Chevron Corp. and HP Labs, said as she led a reporter through a wholesale flower shop that shares access with her office.

In the emerging field of geoengineering, which envisions large-scale efforts to fight climate change by directly manipulating the natural environment, Field’s privately funded Ice911 project is a small player. Under the Trump administration, these eclectic, messianic and mostly untested projects have been gaining unprecedented momentum.

For decades, scientists have warned that unchecked climate change will lead to catastrophes and have urged policymakers to curb greenhouse gases at their source. But politicians have dragged their heels, and under President Donald Trump, progress has slowed. The Trump administration has challenged the scientific consensus on climate, moved to repeal curbs on power plant emissions, proposed sweeping cutbacks to renewable energy research and pledged to withdraw from global climate talks.

Amid these developments, some close allies of Trump have taken a seemingly paradoxical stance: While denying climate change is a human-caused problem and rejecting proposals to cut greenhouse gases, they’re promoting what many experts worry is the risky default solution of geoengineering.

In 2009, John Holdren, President Barack Obama’s science adviser, drew backlash after telling an Associated Press reporter that geoengineering has “got to be looked at.” But since Trump took office, advocates of geoengineering research say the political climate for such tactics has warmed. In December, Rep. Jerry McNerney, a California Democrat, introduced an unprecedented bill seeking funds for geoengineering research and development. In February, Trump signed a budget that includes first-ever tax breaks, with bipartisan support, for using new technologies to capture carbon dioxide from the atmosphere, a strategy many experts consider to be a kind of geoengineering.

“The future is bright for geoengineering,” Republican Rep. Randy Weber of Texas, chairman of the Energy Subcommittee of the House Committee on Science, Space and Technology, said at a hearing in November.

In the past, Weber has grilled scientists on “global cooling” and rejected a carbon pollution tax as “blasphemy.” Yet at the hearing, he claimed that specific, yet-untested proposals such as “placement of mirrors in space” and “brightening the clouds overhead … could have a cooling effect on our lower atmosphere.”

‘Hacking the planet’

Trump himself has not publicly addressed geoengineering, his budget proposals make no mention of it, and none of his cabinet members has publicly endorsed it. Neither Environmental Protection Agency Administrator Scott Pruitt nor Paul Dabbar, the Energy Department’s undersecretary for science, responded to requests for comment.

Nevertheless, said Harvard University physics professor David Keith, “there’s much more broad support for this than there was just two years ago.”