Tuesday, November 19, 2013

Climate Change Driving Weather off the Charts

Meteorologists are calling the typhoon that slammed into the Philippines with 195-mile-an-hour winds on November 8, 2013, the most powerful tropical storm to make landfall on record. Super Typhoon Haiyan had gusts reaching 235 miles per hour and a storm surge swelling as high as 20 feet, so the destruction it left behind matched that of a tornado combined with a tsunami.

Three days later, at the opening of the United Nations climate negotiations in Warsaw, Poland, the lead delegate from the Philippines, Yeb Saño, spoke of the “hellstorm” that left “a vast wasteland of mud and debris and dead bodies.” He continued: “Despite the massive efforts…in preparing for the onslaught of this monster of a storm, it was just a force too powerful and, even as a nation familiar with storms, Haiyan was nothing we have ever experienced before, or perhaps nothing that any country has ever experienced before.”

Haiyan arrived less than a year after Super Typhoon Bopha, which at that point was the costliest storm in Philippine history with $1.7 billion in damages and some 1,900 deaths. Bopha was then outdone monetarily by Trami, which in August 2013 brought the Philippines torrential rains and flooding, leaving some $2.2 billion in damages in its wake. Early estimates put Haiyan’s destruction tab at $14 billion. With more than 4 million people displaced and thousands feared dead, Haiyan looks to be a record on multiple fronts.

The commonly used tropical storm wind speed scale goes up to category 5: more than 156 miles per hour. But as Yeb Saño notes, “if there [were] a category 6, [Haiyan] would have fallen squarely in that box.”

The world is literally moving off the charts. With the global average temperature up over half a degree Celsius since the 1970s and with more warming in store, we are starting to witness weather anomalies so severe we need to update our metrics and extend our graphs.

The warming is the result of a buildup of greenhouse gases in the atmosphere—largely from burning coal, oil, and natural gas—that trap heat from the sun. The extra warmth is taken up by the oceans and also heats the atmosphere, the former faster than the latter, creating a temperature differential that can create more-forceful storms. A warmer atmosphere can hold more water vapor—all the better to produce punishing rainstorms. Warmer sea surfaces provide more energy for storms to grow stronger. The surface waters where Haiyan formed measured up to 1 degree Celsius above normal—that is, until the storm sucked up heat to use as fuel as it passed over the sea.

Physics dictates that warmer water also takes up more space; thus excess heat in the world’s oceans has raised sea level, a process that is compounded by the accelerating melting of the Earth’s polar ice caps and mountain glaciers. By the end of this century, sea level could rise by some 6 feet, making storm surge all the more dangerous.

In recent years, intense storms have showed up in unprecedented locations. Brazil was struck by its first recorded hurricane in 2004, and Spain and the Canary Islands experienced their first-ever tropical storms in 2005. In 2007, a fierce tropical cyclone in the Arabian Sea brought torrential rain to parts of Oman and Iran. In 2008, the first severe tropical storm to hit Myanmar’s densely populated Irrawaddy Delta left 90,000 people dead. And 2012’s Superstorm Sandy was unusual in both its span and its pathway—an unexpected left-hand turn directly into New Jersey.

Like these freak storms, we are in uncharted territory. Big storms occurred prior to human-induced climate change, of course, but raising the Earth’s temperature is like putting the weather on steroids. We might not see more tropical storms, but the ones that form are likely to pack a more-powerful punch. Heat waves are predicted to last longer and become more intense. Rainfall could come fast and furious in some places, while other parts of the globe could see very little at all.

Globally, high temperature records already are being set five times as often as what would be expected in the absence of global warming. In the last decade, daily record high temperatures outnumbered record lows in the United States two to one, and that ratio is increasing. Earlier this year, the Australian Bureau of Meteorology had to add a deeper shade to its temperature mapping color code that had maxed out at 122 degrees Fahrenheit: the Bureau extended the range to 129 degrees after a nationwide heat wave brought scorching temperatures that broke records in every state.

Governments everywhere agreed in 2009 to work to keep the rise in global average temperature below a 2-degree-Celsius threshold to avoid “dangerous” climate change. The United Nations warns that to meet this goal, immediate cuts in greenhouse gas emissions are needed. The problem is that international negotiations move slowly, while temperatures are rising fast—faster, in fact, than at any time since civilization began. The least-common-denominator model of negotiations, in which countries endeavor to concede as little as possible, will just make things worse.

The costs of retooling economies to run more efficiently on renewable energy are negligible compared with the damage the world will incur from runaway global warming. Haiyan and other recent weather extremes are wake-up calls to the urgency of ending our fossil fuel addiction. If we continue to ignore them, the costs of dealing with climate change will surely extend far off the charts. More