John Kerry and Barbara Boxer are two of the greenest members of the Senate. Jim Inhofe is the Senate's chief global warming denier. But last week—on Earth Day, no less—they came together to introduce a bill requiring the EPA to look at ways to control a dangerous pollutant that kills millions worldwide and accelerates global warming, particularly in the Arctic.

No, not carbon dioxide, which remains the main driver of worldwide climate change, but black carbon, airborne microscopic particles of soot. In the United States and Europe, black carbon comes from diesel engines and industrial smokestacks. In the developing world, the main source is primitive cooking and heating fires.

UPDATE: There was a lot of confusion and misinterpretation about Tuesday's announcement by the Environmental Protection Agency that it was reviewing mountaintop removal mining permits to assess their potential impact on the waterways and people of Appalachia. Only two permits have been questioned. Dozens are under review. And the EPA is signalling that many of those may not be held up for environmental reasons.

This is nonetheless a first step towards what we have been petitioning -- and suing -- to have the federal government do. Just this month, nearly 25,000 Earthjustice supporters, along with many others across the nation, sent messages to the White House asking for a halt to this most-devastating method of coal mining.

One year ago in this column, I called on Environmental Protection Agency chief Stephen Johnson to resign for letting politics, not science, guide his agency's decisions. Nor was I alone—10,000 EPA employees were in open revolt for the same reason. Johnson was defying the Supreme Court's ruling that his agency should move forward on climate change and was refusing to approve California's forward-looking controls on climate-altering pollution.

Today, I am calling on all Earthjustice supporters to join with me in thanking his successor, Lisa Jackson, for steering the EPA back on course with a string of good decisions, especially her action last week aimed at regulating one of the most toxic side effects of burning coal for power: coal ash.

Yesterday—10 weeks after a billion-gallon spill of coal ash in Tennessee—two U.S. senators challenged the Environmental Protection Agency to regulate disposal and storage of the toxic sludge.

Sens. Barbara Boxer (D-CA) and Thomas Carper (D-DE) submitted a resolution requesting rules "as quickly as possible" and calling on the Tennessee Valley Authority to "be a national leader in technological innovation, low-cost power and environmental stewardship." On Dec. 22, about 1 billion gallons of coal ash burst through a dam at the Tennessee Valley Authority site in Harriman, flooding more than 300 acres with toxic levels of arsenic, lead, mercury, selenium and boron.

Communities have been exposed to the toxic substance, which presents a cancer risk nine times greater than smoking a pack of cigarettes a day. Yet coal ash is severely under-regulated and exempt from safeguards required of even municipal waste landfills. Earthjustice is calling on the EPA to eventually prohibit the storage of wet coal ash sludge and instead, mandate dry disposal in monitored landfills or safe recycling of the material.