Articles by Joseph Romm

Offsets should be the last thing you need to turn to

Before you pay others to reduce their emissions on your behalf, you need to do everything reasonably possible to reduce your own emissions first. As the saying goes, "Physician, heal thyself," before presuming to heal other people.

This rule is so obvious I almost forgot it. And yet many people, including Google and PG&E, don't seem to get it.

The whole point of offsets is not to make you feel good, and it's not to allow you to continue polluting as much as you want (by, say, supporting new coal plants or other dirty forms of power). Offsets are cheap and in some sense bastardized emissions reductions (more on this in a future post).

In general, the point of offsets is to reduce greenhouse gas emissions, and specifically to allow you to offset any emissions that are left over after you have cleaned up your own act -- or to offset emissions from one-time events such as concerts.

Global warming cancels 4th of July celebrations

Global warming threatens our White Chistmases with winter heatwaves and our Arbor Days with record wildfires. And now it imperils our Independence Day fireworks with ever worsening droughts.

The Drudge Report headline blares "No Fireworks." As USA Today reports:

Dozens of communities in drought-stricken areas are scrapping public fireworks displays and cracking down on backyard pyrotechnics to reduce the risk of fires.

"From a fire standpoint and a safety standpoint, it was an easy call," Burbank Fire Chief Tracy Pansini says. He recommended calling off fireworks at the Starlight Bowl because they're launched from a mountainside covered with vegetation that's "all dead."

The record droughts around the country have nixed fireworks in a half dozen states. What will happen to 4th of July celebrations over much of the country if, as predicted in an April Science, article, we have "a permanent drought by 2050 throughout the Southwest"?

Here are some of the places canceling fireworks this year:

Emphasis on the ‘rare’

Trees are terrific in every way but one: they make lousy carbon offsets. That was the point of the "First rule of carbon offsets." But a number of comments and some media queries have led me include two rare exceptions: certified urban trees and certified tropical forest preservation. The word "certified" is key in both cases.

For these two rare cases, I would allow trees to comprise no more than 10 percent of an overall offset portfolio (which should be heavily weighted toward efficiency, renewables, fuel switching, and perhaps carbon capture and storage). Also, their offset value should probably be discounted over time (because urban trees are unlikely to be permanent and tropical forest accounting is quite uncertain).

A good reason we shouldn’t love trees, at least not in this case

Everybody loves trees. They are so popular as offsets they even make Wikipedia's definition:

When one is unable or unwilling to reduce one's own emissions, Carbon offset is the act of reducing ("offsetting") greenhouse gas emissions elsewhere. A well-known example is the planting of trees to compensate for the greenhouse gas emissions from personal air travel.

But does planting trees reduce global warming? Not in most places on the earth. The Carnegie Institution's Ken Caldeira summarized the result of a major 2005 study (PDF) this way: "To plant forests to mitigate climate change outside of the tropics is a waste of time."

Why? Because forest canopies are relatively dark, compared to what they replace outside the tropics -- grass, croplands, or snowfields -- and so they absorb more of the sun's heating rays that fall on them. That negates the "carbon sink" benefit trees have soaking up carbon dioxide. Worse, the study found that planting a large number of trees in high latitudes would "probably have a net warming effect on the Earth's climate." Ouch!