Lo and behold, the leaders of the two largest emitters of greenhouse gases came to an agreement to address the problem of climate change. Was it a visionary and bold plan to address emissions from the energy sector? No.

The Arctic is warming more than twice as fast as the rest of the planet, pushing species toward extinction, accelerating ice melt and sea level rise, and amplifying climate change worldwide.

In his inaugural address this week, President Obama committed us to get back to work on the challenge of a sustainable energy future. But will this reignite the debate on climate change or have three widely publicized stories already done that for us?

For the past two decades, NRDC's Dump Dirty Diesels Campaign has been working in the U.S. and internationally to solve the problem of dirty diesel exhaust.

From Climate Central's Michael D. Lemonick: No discussion of climate change can get very far without focusing on greenhouse gases — pollutants in...

You may hear it called black carbon or even elemental carbon. Scientists getting technical will call it the "light-absorbing part of particles suspended in the atmosphere." Let's just keep it simple and call it soot.

You have probably heard about melting Arctic ice and the drastic decrease in glacier size. And while you may be aware that the increase in greenhouse gases is to blame, at least in large part, you may not realize that a substance called black carbon is an accomplice.

Unexpected threats to the health of global systems keep emerging and this might be the landmark week in which a broad public recognized a new threat to the global climate: black carbon.

Send all your eco-inquiries to Jennifer Grayson at eco.etiquette@gmail.com. Questions may be edited for length and clarity. Somebody said to me that ...