Matt Yglesias

Measuring Forest Conservation

Deforestation in Nigeria (Foreign and Commonwealth Office photo)

The United Kingdom’s Eliasach Report on deforestation and climate change concludes that “Using appropriate techniques, forest emissions can be estimated with similar confidence to emissions estimates in other sectors.” Glenn Horowitz explains the significance of this:

That’s very good news, as approximately 20 percent of total global warming pollution comes from deforestation, more than all the world’s cars, trucks, planes, and ships combined. As the United States and the world move towards a system in which these forests are valued for their immense carbon storage, it’s critical that we make those valuations as accurate as possible—so we can know exactly how much a particular forest conservation project (and ultimately a particular country) is actually reducing emissions.

Of course, there’s a key caveat in The Eliasch Review’s conclusion: “using appropriate techniques.” Although these appropriate techniques are available and have been applied in many projects, deploying them at the global scale needed to end deforestation will require financial and human investment.

The investment involved is pretty modest (”the costs of monitoring forest projects are typically less than $1 per ton of carbon reduced, often much less”) but the time scale is quite urgent since deforestation is proceeding very rapidly. What’s more, you tend to have your most severe deforestation issues in countries where the overall quality of governance is low. That tends to make it difficult in practice to do things even if they’re cheap and technically feasible.

6 Responses to “Measuring Forest Conservation”

1. Bob Roddis Says:
   October 19th, 2009 at 3:53 pm

   Plant more trees. I second that.

   Can we all agree?

2. yoyo Says:
   October 19th, 2009 at 4:37 pm

   no, trees are bad and cause pollution!

3. Teemu Says:
   October 19th, 2009 at 5:08 pm

   It’s difficult to find that “appropriate technique”, since there’s always some country that gets treated unfairly.

   For example, one technique is to take comparison period (say, 2005-2006) and calculate the net sum of carbon that forests have either sucked in or spewed out during that period. Then you keep doing these calculations and compare the future years to comparison period, to see whether there’s been any change and to what direction.

   Finnish paper mills had a long strike on 2005-2006. As there was no need for raw materials, the net forest growth during that period was huge. If that period is used as comparison period (as has been suggested), then typical annual net growth (moderately positive) is seen as drastic step to worse, thus causing us to get punished.

   So, there’s a danger that some growing forests indeed will be counted as pollutants…

4. Midland Says:
   October 19th, 2009 at 9:48 pm

   no, trees are bad and cause pollution!

   Go lie down, Ronnie, you’ve been dead for years.

5. Kolohe Says:
   October 20th, 2009 at 2:11 am

   I don’t get this. It’s like saying the expense of a glucose meter is what limits treating diabetes.

   As you concluded with, the solution to the problem deforestation is fixing bad goverenance and especially the poverty of the places where it is a problem. Measurement has little to do with it.

6. Gar Lipow Says:
   October 20th, 2009 at 3:39 pm

   I guess in a way better measurement is always good news. But what the headline seems to imply is that measurement is precise enough to allow deforestation and degradation to be included in cap-and-trade. And if you pierce beyond the headline to the actual report that is still not true. The absolute best precision they report is with initial carbon stock which they claim can be measured plus or minus 3%. That sounds good, but the problem “initial stock” is a dynamic number. Forests breathe in an out all the time. Initial stock on one day is different from initial stock on another. If you look in the previous section on constructing baselines (essentially stories against which to measure changes) you will see all sorts of discussions of averaging methods, and why the politics of choosing such scenario construction are as important as the science.

   The next most precise measurement is of land use changes, and here they claim plus or minus 7%. (Again an important caveat – that plus or minus 7% is dynamic. That is there would be some changes even with no human intervention, and with no catastrophes. There is a natural carbon cycle going on too, even though we have overlaid a lot of human caused changes on it.)

   And lastly there is degradation, as opposed to actual land use change. And this is the hardest to measure of all imprecision as high as 20%.

   Now these numbers – 3% for stocks, 7% for land use changes, 20% for degradation don’t sound like large degrees of imprecision. Until you consider that most mainstream proposals for cap and trade don’t propose lowering emissions by more than 3% year year. The most radical proposals suggest 8% to 10% reductions annually. So even stock measurement, where precision is greatest, has inaccuracy equivalent to 100% many reduction proposals. And degradation measurement has inaccuracy equal to 200% of even the most radical proposals. Which means that you cannot in fact include forestry and deforestration in cap-and-trade.

   And again all these accuracy measurements are worse than they seem, because forestry carbon is dynamic, meaning measurement on a particular day is not as meaningful as the same sort of measurement when burning fossil fuel. Carbon in fossil fuel in the ground is only released if the coal is mined or the oil or gas well is drilled. With trivial exceptions, you know that if you leave the coal in the hole or the oil in the well, the carbon won’t be released. With forestry it is not that simple, so all these measurements are less meaningful even than they seem.