Notes from the 2005 Pop!Tech Conference, Camden, Maine

Mark Lynas

Human Cost of Climate Change

Marklynas.org

It's very easy to put each other in boxes. But climate change isn't an issue where you can do that. Climate change is the whole of the human species vs. the biosphere. We're used to human vs. human, this is different.

Temps globally are higher than they have been for 5000 years. Because we've moved the earth so far outside the climactic boundaries, climatologists now say that we have moved into a new epoch in the history of earth, the epoch dominated by a single species-us.

It seems like the Day After Tomorrow-we just had the strongest hurricane ever in the Atlantic basin.

Now, anecdote doesn't replace data, but it supplements data when the data is already well established, as it is. So let's tell some stories.

I was in the Peruvian Andes, on a glacier that is a great reservoir of water for the Peruvian people. It's receding exceedingly fast (shows a before/after image). In the glacial lake that is runs in to, you can see the glacier has receded by about half a kilometer since 1980. The images are indeed striking, the barren rock left over from the beautiful ice.

All the water that Lima depends on comes from the river valleys. There's a glacier that supplies the water from all of Lima, a city of 7 million people-the largest desert city besides Cairo. And this glacier is receded by kilometers.

World glacier foundation found that 97 percent of world's glaciers are receding.

When you add this water to the thermal expansion of seawater, you get rising sea levels. Take Tuvalu, in the South Pacific. We've had just a few cm of sea level rise in the 20th century, but it threatens to flood the island all the time. You get water that now pushes up through the ground in the middle of the island. This is a survival problem for Tuvalu. It's losing coconut trees from the shore, for example. The new Prime Minister is moving people off the island to New Zealand because the island is doomed.

Shishmaref, Alaska. North of Alaska. Houses built on the cliffs of the barrier island are falling off, as the water doesn't freeze, and waves erode the shore.

Fairbanks. The ground has melted underneath places so much that buildings are falling over.

He's now trying to bring together all the scientific papers that predict what we're in for. He shows the hockey stick graph, showing exponentially rising temps. It predicts up to 6 degrees of global warming.

One degree: Code Blue. The likely extinction of all coral reefs. Already the Great Barrier Reef is bleached. Nebraska was a desert 9000 years ago, might become one again. By 2025. This level of climate change is unavoidable.

Two Degrees: Code Green. Will lose glaciers, some reserves.

Three Degrees: Code Yellow. A crisis of biodiversity. Mass extinctions. By 2050, 1/3 of all species could be extinct (published in Nature). Whole of Greenland ice sheet will melt. Will give us 6 meters of sea level rise. That would flood much of florida. Huge areas of the east coast would be inundated. Amazon rainforest will tip into a new regime where it turns into desert. Carbon in the plant life goes into the atmosphere, creates positive feedback.

Four Degrees: Code Orange. Arctic sea ice gone in summer-all mammal life in artic is extinct.

Five Degrees. Code Red. All glaciated mountains in Nepal, the source of the Indus river, that which keeps all of Pakistan going, will be gone. 100 million people will die or be displaced. How will this affect global stability? The Larsen B ice shelf will collapse (it's already happening).

Last time in history when we had such levels of global warming was in Eocene-55 to 36 million years ago. That was last time atmospheric CO2 was above 500ppm.

Six Degrees: Code Black. Who knows? Last time we had this 95 percent of life was wiped out in the Permian extinction.

We must take this issue much more seriously if we are to survive as a species.