I manage Restore Mass Ave, an environmental non profit that adds urban forest​ in Washington DC. Debthink is my personal site for posting about science policy, climate and other topics, with info about my books.

Entries in sea level rise (4)


Warming will be worse, scientists warn, but Americans wait for the movie  

October 2009

Does new evidence of warming count as news?

This just  in.

Global warming is causing Earth’s systems to change faster than the most sobering predictions of a few years ago. Drastic changes that had been expected over long periods, such as the melting of Greenland’s glaciers, are occurring sooner.

And a respected model forecasts that, by 2100, average global temperature may rise by 4 °C (6.3° F) even if all nations carry out the cuts in carbon dioxide equivalent (CO2e) emissions they’ve pledged. A 4°C rise by 2100 would be twice the 2°C increase over preindustrial levels that world leaders declared in L’Aguila, Italy as the acceptable maximum.

These messages came through loud and clear at a press event

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On vacation, learning to love seaweed

August 2009

Tassels of brackish, dark seaweed stretch ahead of me, baking in the summer sun. I’m tempted to look up across Goleta Bay’s dark waters to the dusty blue of the Santa Barbara Channel. But I keep my eyes down to pick my way through the detritus of shells, stones, and insects, as my city feet are tend er.  It’s a lovely afternoon. The temperature is 68° F (20° C). The breeze wafts coolly from the sea. I think: Life’s a beach.

This beach is alive, actually. The dark mounds are mainly heaps of giant kelp. Explaining kelp’s importance as she leads me among the piles is Jenifer E. Dugan, a sandy beach scientist who is an Associate Research Biologist at the Marine Science Institute of the University of California at Santa Barbara. The roofs of the university buildings peek at us over the 40-foot high bluff.

Jenifer E. Dugan points out "wrack". (Author photo)

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Grand Canyon thoughts: Could humans start a new geological age?

August 2009

In dawn’s early light it was dim and cool on the porch. But my usual stroll across the lawn to the edge of Grand Canyon was blocked by four large animals grazing, as if the lawn was theirs not mine.   

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Hansen: Earth’s climate nears the tipping point

June 2008    Updated in my blog post Should Scientists Attack the Cap and Trade Bill?

Like many who graze news stories about ways the United States might respond to global warming, I thought Congress would do well to pass any of the proposed bills to cap US emissions of carbon dioxide (C02), the principal greenhouse gas. I assumed that neither the specific level of reduction nor the exact timing mattered—so long as Congress acted soon.

But on June 23, I heard NASA scientist James E. Hansen argue that we’re approaching a point where planetary impacts will be irreversible.

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