Three Takes on Climate Change

What’s your side of the story and your political position? Last week, NPR’s All Things Considered featured two professional views on climate change– the ‘consensus view’ and the ‘uncertain’ side… different opinions on the same topic, preparing for the Intergovernmental Panel on Climate Change’s (IPCC) release of their fifth consensus report. Read or listen to theses stories and share your thoughts, then take a moment to localize them. The Colorado Foundation for Water Education offers our Citizen’s Guide to Colorado Climate Change, web content on Colorado’s climate and a Climate Tour in early 2014 as resources to help you delve further into Colorado’s climate future.

From our website:

Climate change will bring huge impacts to Colorado’s water, which in turn will affect our way of life – the water we drink, the water for our crops and livestock, the water for our forests and wildlife, the water and snow we count on for recreation. Not everyone agrees on the causes of climate change, or the degree to which it is taking place. But climate change of any degree will require us to change how we manage and use water.

Scientists are predicting warmer temperatures for Colorado. While it is difficult to predict specific changes to precipitation, warmer temperatures will likely mean less water. Less water will have enormous consequences for Colorado, especially as increasing demands put additional pressures on this limited resource.


Publication2climate fact 1 As All Things Considered demonstrates through their two stories, this scientific debate has become political. Take a look– first, the ‘Consensus’ View of Colorado’s own Kevin Trenberth. Trenberth has been part of the IPCC since it’s early days in the 1990s and is a senior researcher at Boulder’s NCAR. From All Things Considered:

The oceans can at times soak up a lot of heat. Some goes into the deep oceans where it can stay for centuries. But heat absorbed closer to the surface can easily flow back into the air. That happened in 1998, which made it one of the hottest years on record.

Trenberth says since then, the ocean has mostly been back in one of its soaking-up modes.

“They probably can’t go on much for much longer than maybe 20 years, and what happens at the end of these hiatus periods, is suddenly there’s a big jump [in temperature] up to a whole new level and you never go back to that previous level again,” he says.

You can think of it like a staircase. Temperature is flat when a natural cool spell cancels out the gradual temperature increase caused by human activity. But when there’s a natural warm spell on top of the long-term warming trend, the story is dramatically different.

In addition to this scientific perspective, Ternberth has seen the role of the scientist expanding into the political arena. Scientists like him are trying to reduce the risk of climate change by pushing society to take action. From the article:

“This is very much in the role of the politicians who are supposed to do what’s in the interests of everybody as a whole,” Trenberth says. “And I’m not so sure many politicians understand their role in this.”

There’s a deep current on Capitol Hill that says it’s pointless even to try; because China and India seem destined to produce so much carbon dioxide, curtailing U.S. emissions won’t do much at all. But wading into this policy debate, Trenberth argues that the United States could and should lead the world toward a less dangerous trend.

While, on the other side, ‘Uncertain’ scientist Judith Curry, profiled in another All Things Considered story, has pushed for just the opposite. The U.S. Congress has remained steadfast against taking action to deal with climate change, and called Curry, an ally, to testify at a subcommittee hearing this spring. Curry’s message is that we just don’t know enough to take action.

From All Things Considered:

She says there’s so much uncertainty about the role of natural variation in the climate that she doesn’t know what’s going to happen. She says a catastrophe is possible, but warming could also turn out to be not such a big deal.

And she focuses on uncertainties and unknown unknowns far more than on the consensus of climate scientists, who say we know enough to be deeply worried.

“I’ve been trying to understand how there can be such a strong consensus, given these uncertainties,” she told the committee.

Her message that day on Capitol Hill was, in essence, that while humans may be contributing to climate change, we simply don’t know how the climate will behave in the coming decades, so there may be no point in trying to reduce emissions.

Curry’s political position is grounded in economics and individualism:

“I have six nieces and nephews who have recently graduated from college,” she says. “Not easy finding jobs in this economy. Are we going to jeopardize their economic future, and we don’t know if they’re going to care and if this is going to matter?”

Of course doing nothing to address climate change is actually doing a lot. Carbon dioxide levels are growing fast in the atmosphere and are destined to double or triple over pre-industrial levels. Curry acknowledges that.

“I don’t know how concerned I should be about it — on what time scale that might happen, whether that’s 100 or 200 years, what societies will be like, what other things are going on with the natural climate,” Curry says. “I just don’t know what the next hundred or 200 years will hold, and whether this will be regarded as an important issue. I just don’t know.”

So, you have two perspectives, what’s yours? Maybe broaden it… although Ternberth focuses on oceans, and of course, threat of climate change in Colorado is much different than what it could mean in coastal areas. Take a look at this National Geographic article on rising seas to hear about impacts in different parts of the world.

Global warming affects sea level in two ways. About a third of its current rise comes from thermal expansion—from the fact that water grows in volume as it warms. The rest comes from the melting of ice on land. So far it’s been mostly mountain glaciers, but the big concern for the future is the giant ice sheets in Greenland and Antarctica. Six years ago the Intergovernmental Panel on Climate Change (IPCC) issued a report predicting a maximum of 23 inches of sea-level rise by the end of this century. But that report intentionally omitted the possibility that the ice sheets might flow more rapidly into the sea, on the grounds that the physics of that process was poorly understood.

As the IPCC prepares to issue a new report this fall, in which the sea-level forecast is expected to be slightly higher, gaps in ice-sheet science remain. But climate scientists now estimate that Greenland and Antarctica combined have lost on average about 50 cubic miles of ice each year since 1992—roughly 200 billion metric tons of ice annually. Many think sea level will be at least three feet higher than today by 2100. Even that figure might be too low.


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