Q and A: Forests and Climate

Reading about declining forests, the problem seems overwhelming. So I’m wondering: What can I do at a personal level?

Many readers asked variations of this important question. Policy experts agree that voluntary, individual action is never going to solve the problems of forests, much less the larger problem of climate change. If these problems are to be solved, it will be through some heavy lifting that harnesses government and corporate power over the course of decades, they say, and it will cost all of us money.

But that said, on the larger problem, climate change, you have considerable control over your own carbon footprint should you wish to reduce it. Dozens of organizations offer recommendations on how to cut it, but the most thorough and scientifically grounded advice I have seen came last year from the Garrison Institute and the Natural Resources Defense Council. A write-up of the project is here, and this Web site walks you through their recommendations.

On the question of forests, you are free to choose wood products certified to have been harvested in a sustainable way — for example, by the Forest Stewardship Council, which has major environmental groups sitting on the board as watchdogs. The Home Depot, among many companies, offers an extensive line of F.S.C.-certified products.

As for eating decisions, agriculture is the reason for a lot of tropical deforestation. Consumers are beginning to demand that major food companies put pressure on their supply chains to halt deforestation, and the companies are starting to react to that pressure. Some consumers write food companies to let them know where they stand.

Finally, I’m going to risk sounding like a civics teacher with this, but it’s really true: Congress is going to pass national policies to limit carbon emissions if, and only if, the American people demand it by exercising the power of the ballot.

Do you think that enough is being done to control/reduce the population of the world? And what else could be done?

It is certainly true, as several readers pointed out, that many of the world’s environmental problems, including climate change and the stress it is creating for forests, are ultimately rooted in the explosive population growth of the past century. My colleague Celia Dugger and I wrote recently about the latest United Nations population projections, which are sobering.

But, that said, the population growth rate for the world as a whole peaked in 1963 and has been falling as more and more countries go through the great shift known as the demographic transition.
(Here is an explanation, and here is the classic paper that introduced this concept.)

The only true population-growth hot spots that remain are in South Asia and sub-Saharan Africa. Focused programs to empower women in those regions with knowledge and access to birth control could certainly bring growth rates down there, benefiting those societies as well as the world at large, policy experts say. Some people are trying to get such programs back on the international agenda in a bigger way.

Does it seem like the forests of America are destined for the same fate as the Arctic ice caps, being that the government will do nothing about it?

When I was flying over Montana in a small plane with the scientist Steven W. Running, I was awed by the devastation we were seeing across one mountainside after another, and kept saying so. At one point, yelling over the engine roar, Dr. Running shut me up with a simple observation: “Look how much is left!”

His point was that the situation is not hopeless, and I came to see that he was right. I emphasize again, as I said in the article, that the forests of the world are continuing to take up a large amount of carbon. Even given all the problems we are seeing in the American West and in other affected regions, the healthy forests still outnumber the sick ones. Policies and action are needed to help them stay healthy, scientists say. So my answer to your question is: I just can’t bring myself to be that pessimistic.

Is the pine beetle a native insect? If so, why doesn’t it have a predator? Is any conifer resistant to them?

As I said in the article, the mountain pine beetle is in fact native to the forests of the West. It evolved millions of years ago to exploit an ecological niche, and it has caused large outbreaks of destruction in the past — but, so far as we know, none as large as this one.

Pine beetles do have several predators (go, woodpeckers!), and some trees have defenses against them, including lodgepole pines. But when the beetles become numerous enough, as they have in recent years, they can swarm a tree in such numbers that they overwhelm those defenses. Several factors have contributed to the scale of the current outbreak. Among the most important is the warming climate, which is removing a natural control on beetles: deep winter freezes.

When I sent him your question, Werner A. Kurz, a leading Canadian scientist, wrote back that while the beetle is indeed native to the region, “it has experienced an expansion in range northward and to higher elevations as climate warming has allowed the species to occupy areas that were previously too cold.”

The beetle is now wiping out a whole ecosystem, high-elevation whitebark pine forests, that saw only limited beetle outbreaks during warm spells in the past. It has jumped into a new tree species, the jack pine, that could give it a path to spread across the continent in coming decades, into forests that have no defenses.

Your video shows areas of Arizona where trees are not growing back. Why can’t trees be planted there artificially?

That does happen, actually, across large parts of the West after forest fires or other disturbances. But artificially replanting forests is expensive, which limits how much of if the Forest Service can do. Moreover, the agency has sometimes run into criticism from scientists over what they describe as “political replanting” projects that do not always make ecological sense.

In an area that was already at the edge of a particular tree’s natural climatic range, the warming and drying of recent years may have created conditions that can no longer support a forest. That means transplanted seedlings are not going to survive, and planting them would therefore be a waste of money.

What we are seeing in the Southwest is a fairly extensive conversion of forests into grasslands and shrubs, which are inherently more resistant to dry, warm conditions. This is a natural response to an unnatural situation, a change in the climate caused by human emissions of greenhouse gases. It is worrisome not only because the landscape can store less carbon in shrubs and grasses, but as a confirmation that the climate is indeed changing in harmful ways.

What if all of us filled our yards with trees?

We got several variations on the question of whether it helps to plant trees. Short answer: Yes. Long answer: Planting appropriate types of trees, at the correct density, in spots that can support them is a good idea for many reasons, with carbon storage being only one. But let’s face it, planting one tree, or even a thousand, is not going to make much difference to the world’s overall carbon problem.

Budging the global numbers even a little by this method would require planting trees, or allowing them to regrow naturally, across millions of acres that currently do not support them. This is called afforestation, and as I mentioned in the piece, it has already happened on a large scale in the eastern United States, the former Soviet Union, China and some other areas. It is also happening, surprisingly, in areas where tropical forests were chopped down in prior years — left alone, those jungles recover robustly and become carbon sponges.

But most of the scientists I spoke to tended to think we have gotten most of the bang we’re going to get out of this approach. The areas that would be most suitable for new forests are being used today as farmland, and with rising global food and biofuel demand, the prospect of converting large amounts of it back to forest appear to be remote.

Daniel C. Nepstad, an American scientist working in Brazil to understand the Amazon, often describes the situation as an incipient global land crisis. We have more potential uses for land, forests being one, than land available.

Please let us know, can a tree converted to wood pulp and then converted to newsprint store the same amount of carbon as a living tree?

I’m going to take this as a sarcastic question. But I accept your point: newsprint has historically been one of the biggest sources of demand for pulp, and that demand led to the destruction of many native pine forests in the region where I grew up, the South. Across millions of acres, once-rich ecosystems have been replaced by pine plantations that are turned over so fast they resemble corn farming.

While I haven’t seen a formal carbon accounting for the newsprint industry, it is hard to imagine that the numbers would be favorable. But that said, I will note that newspapers have achieved the highest recycling rate of any type of paper product, close to 75 percent. Moreover, if newsprint troubles your conscience, it is now possible to go entirely digital in reading this one.