An Expedition Through Manhattan Explores the Effects of Climate Change

The New York Times' superb science columnist, John Tierney takes a walk with Skeptical Environmentalist Bjorn Lomborg through Manhattan to the Bridge Cafe to explore the effects of climate change. Here is some of what he found about the effects of sea level rise:

Since record-keeping began in the 19th century, the sea level in New York has been rising about a foot per century, which happens to be about the same increase estimated to occur over the next century by the Intergovernmental Panel on Climate Change. The temperature has also risen as New York has been covered with asphalt and concrete, creating an "urban heat island" that's estimated to have raised nighttime temperatures by 7 degrees Fahrenheit. The warming that has already occurred locally is on the same scale as what's expected globally in the next century…

The impact of these changes on Lower Manhattan isn't quite as striking as the computer graphics. We couldn't see any evidence of the higher sea level near the Bridge Cafe, mainly because Water Street isn't next to the water anymore. Dr. Lomborg and I had to walk over two-and-a-half blocks of landfill to reach the current shoreline.

And his findings about the effects of higher temperatures and mortality:

The first is that winter can be deadlier than summer. About seven times more deaths in Europe are attributed annually to cold weather (which aggravates circulatory and respiratory illness) than to hot weather, Dr. Lomborg notes, pointing to studies showing that a warmer planet would mean fewer temperature-related deaths in Europe and worldwide.

The second factor is that the weather matters a lot less than how people respond to it. Just because there are hotter summers in New York doesn't mean that more people die — in fact, just the reverse has occurred. Researchers led by Robert Davis, a climatologist at the University of Virginia, concluded that the number of heat-related deaths in New York in the 1990s was only a third as high as in the 1960s. The main reason is simple, and evident as you as walk into the Bridge Cafe on a warm afternoon: air-conditioning.

So what to do about global warming:

The lesson from our expedition is not that global warming is a trivial problem. Although Dr. Lomborg believes its dangers have been hyped, he agrees that global warming is real and will do more harm than good. He advocates a carbon tax and a treaty forcing nations to budget hefty increases for research into low-carbon energy technologies.

But the best strategy, he says, is to make the rest of the world as rich as New York, so that people elsewhere can afford to do things like shore up their coastlines and buy air conditioners. He calls Kyoto-style treaties to cut greenhouse-gas emissions a mistake because they cost too much and do too little too late. Even if the United States were to join in the Kyoto treaty, he notes, the cuts in emissions would merely postpone the projected rise in sea level by four years: from 2100 to 2104.

"We could spend all that money to cut emissions and end up with more land flooded next century because people would be poorer," Dr. Lomborg said as we surveyed Manhattan's expanded shoreline. "Wealth is a more important factor than sea-level rise in protecting you from the sea. You can draw maps showing 100 million people flooded out of their homes from global warming, but look at what's happened here in New York. It's the same story in Denmark and Holland — we've been gaining land as the sea rises."

But what if global warming is worst than the Intergovernmental Panel on Climate Change projects:

The biggest limitation to his cost-benefit analyses is that no one knows exactly what global warming will produce. It may not be worth taking expensive steps to forestall a one-foot rise in the sea level, but what if the seas rise much higher? Dr. Lomborg's critics argue that we owe it to future generations to prepare for the worst-case projections.

But preparing for the worst in future climate is expensive, which means less money for the most serious threats today — and later this century. You can imagine plenty of worst-case projections that have nothing to do with climate change, as Dr. Lomborg reminded me at the end of our expedition.

"No historian would look back at the last two centuries and rank the rising sea level here as one of the city's major problems," he said, sitting safely dry and cool inside the Bridge Cafe. "I don't think our descendants will thank us for leaving them poorer and less healthy just so we could do a little bit to slow global warming. I'd rather we were remembered for solving the other problems first."

Whole New York Times article here.

Some of my own reporting and opining about the role of wealth in ameliorating future global warming here and here.