San José, Costa Rica, since 1956

Climate change is nuanced, UN expert says

Ask any farmer what’s hurting the crop lately and he will probably tell you it is a combination of factors stemming from climate change. Unseasonable dry spells. Relentless rains. It’s said that these are startling messages that climate change is alive and dangerous, taking its toll on production.

“We’ve seen it stop raining when it should be raining and then it rains a lot when it’s not supposed to so much,” said Guatemalan coffee grower Ricardo Villanueva. “It’s a problem with the change in climate.”

However, while global warming is under way, those weather swings – largely brought on by phenomena known as El Niño and La Niña – should not be too hastily blamed on climate change, says the United Nation’s top meteorologist.

Such an utterance could seem unexpected coming from Michel Jarraud, the French secretary-general of the World Meteorological Organization (WMO), which for years has warned of global warming.

In a recent exclusive interview with The Tico Times, Jarraud said scientists still have a long road ahead to better explain nature’s wrath as seen in such events as the damaging tropical storms Tomás and Nicole in 2010, or the crop-crippling drought of 2009.

Last year, harsh weather left countries on this narrow isthmus with hundreds of people dead and hundreds of millions of dollars in repair bills. The impact on agriculture – the bulk of the region’s livelihood – was particularly hard.

Costa Rica’s National Meteorological Institute (IMN) predicts a slightly milder rainy and hurricane season, with rainfall dropping by 17 percent below last year’s levels and hurricanes down to 12 from 14.

These immediate trends are superimposed over a long-term phenomenon, according to the U.N.’s weather chief. One might not necessarily explain the other as is popularly thought.

“From year to year you can see big variations which are not due to climate change,” Jarraud said on the sidelines of a meteorology conference at San José’s Radisson Hotel earlier this month.

But even Costa Rica, which prides itself on nature-friendly policies, has not been spared the impact of climate change. Comparing data from the periods of 1961-1990 and 1991-2005, the IMN found that average temperatures climbed a whole degree Celsius in parts of the country. Scientists and politicians argue that Central America is especially vulnerable to climate change and needs special help from major industrialized polluting nations to stem the effects.

This is not a climate skeptic talking. It’s the same meteorologist who stresses that last year was the warmest on record in more than 150 years of documenting. The year 2010 is nearly tied with 2005 and 1998. Worse, the start to the millennium so far is the hottest decade since the world began taking note.

And he forcefully avers, to skeptics’ chagrin, that global warming is largely the product of human activity, and the gradual uptick in temperatures has accelerated in the past 20 years. It does not make for easy listening.

Jarraud also has insisted on understanding the nuances: “Just as one cold snap does not change the global warming trend, one heat wave does not reinforce it,” he wrote in The Washington Post in 2009.

The snaps, waves and more destructive weather systems will grow more common and fierce, however.

“It is likely that the number of extreme events will increase in frequency and intensity, like in some parts of the world floods, and in another part of the world droughts or heat waves,” he said.

He envisions that by 2050 an average year could be like 2003, when natural and man-made catastrophes killed as many as 60,000 people worldwide.

Unfortunately for Costa Rica and its neighbors, the “majority view of scientists” is that hurricanes will grow worse as well, whipping up category 4s and 5s more often than ever before.

Again, even on this front, Jarraud hesitates to sound too conclusive.

“Is there any impact of climate change on hurricanes? It’s a very difficult answer,” he said, acknowledging that “a lot of research is being done and the answer will get better and better.”

For answers, Jarraud said it’s important to measure periods of 10 to 30 years. In that timeframe, he believes, global warming is stark clear. He argues that growing evidence of human’s hand in climate should be enough to win over the skeptics.

“We have not had as much CO2, methane, nitrogen oxide [in the atmosphere] for at least 800,000 years,” he said. “And we know that with great precision because you can analyze the air that is trapped in ice cores in Antarctica […] and analyze the chemical composition of very old air. It’s not a hypothesis; it’s a fact.”

Slowing the Change – Slowly

Following the U.N. Climate Change Conference in Cancún, Mexico last December, observers widely lauded the event as a quiet triumph over the hyped-up talks two years prior in Copenhagen, which were considered a failure. That’s partly because in Cancún countries zeroed in on a target limiting temperature rises to 2 degrees Celsius and a timetable for review to ensure global climate action.

Christiana Figueres, a Costa Rican who is the head of the U.N. climate change secretariat, said of the outcome, “It is not what is ultimately required but it is the essential foundation on which to build greater, collective ambition.”

Jarraud hopes for further work in November at the next climate conference in Durban, South Africa.

“I was encouraged by the Cancún conference because the momentum was back in this negotiation, and I think there’s a will of many governments,” he said. “I hope the momentum will accelerate in the next conference.”

The temperature cap is nothing to sneeze at. A rise of 2 to 5 degrees would cause damage in Central America estimated at $73 billion – equal to more than half of its 2008 economic output, according to a climate report by the U.N.’s Economic Commission for Latin America (TT, Dec. 8, 2010).

Jarraud is cautiously hopeful of meeting the 2-degree limit but acknowledges an immense task ahead.

“It’s still feasible but it’s very, very challenging, and the more countries wait the more difficult it will be to stay under 2 degrees,” he said. He did, however, point out another subtlety: “Two degrees, bear in mind, is not uniform; it may be 4 degrees in some places and 1 degree in other places.”

Despite hopes of the negotiations progress, scientists have resigned to accept a bleak picture: it may be too late to reverse what damage is already done.

“Even if we were to stop all emissions of greenhouse gases tomorrow, still there would be a certain amount of warming because of what has already been sent into the atmosphere,” he said.

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