Meg mentioned in Wired News article:
Will forests slow global warming – or speed it up?
Everyone knows that forests are good for the environment. By removing carbon dioxide – the principal cause of global warming – from the air, trees grow. And the bigger and more plentiful the trees, the more CO2 they sequester. This makes forests a helpful bulwark against climate change. But despite the best carbon-eating action of our flora, the planet is heating up. This raises the specter of a future in which, paradoxically, forests don’t reduce climate change but – as they are destroyed – make it worse.
We don’t know which way it will go, because we know so little about forests themselves. Scientists estimate that up to 50 percent of all species live in forest canopies – three-dimensional labyrinths largely invisible from the ground – but virtually no one can tell you what lives in any given cubic meter of canopy, at any height, anywhere in the world. We don’t even have names for the most common species of trees in the Amazon.
But scientists can readily foresee the way in which these carbon killers instead become dangerous carbon spewers. As the climate warms, many forests will become drier, putting the trees under stress. Typically, this sets the stage for huge outbreaks of insects, which can strip trees of their leaves, killing large numbers of them. Once dead, trees release their carbon into the air – already roughly 25 percent of the greenhouse gases pouring into the atmosphere come from forests that are burned or cut down. Further, if they no longer exist, forests can’t absorb CO2 anymore, and the bare ground that is exposed heats up faster – forests are like giant swamp coolers for the planet. Will this happen? Hard to say. If we don’t know which insects are eating the leaves now, we can’t gauge how global warming will affect them or how they in turn might affect forests. “You can’t possibly answer more general questions about forests until you at least know what lives there,” says Margaret Lowman, canopy scientist at New College of Florida. “It’s more than just giving names to things. We need to know what’s common and what’s rare, and what these species are doing, before we can go to the next level, which is to try to see the interaction between forests and Earth’s climate.”
