Recognizing a Changing Climate

The ‘R’ in my RAMA Initiative stands for recognition. Recognition, Attribution, Mitigation, Adaptation–cute, huh?)

Recognizing a changing climate is easy because the climate is always changing. If it wasn’t we wouldn’t study it so carefully.

Recognizing unusual changes and even a pattern of unusual changes is an important part of the climate debate. It’s important because it is logical to assume that human actions are influencing the climate. In 1945 there were 5 million cars on the planet. There are now 1 billion. From coal-fired power plants to washing machines we have exponentially increased our emissions of CO2. We have cut down forests, built dams, freeways and huge cities. Without exaggerating our importance it is still safe to assume that what we have done has had some effect. But can we see it?

Starting in 2005, scientist Kevin Trenberth began writing that storms, heatwaves, floods and droughts were partially influenced by the climate changes seen since 1945. I dubbed it ‘Xtreme Weather’ and have been extremely skeptical of Trenberth’s desire to reverse the null hypothesis and automatically attribute some percentage of whatever the weather brings to human contributions to our changing climate. Floods in Pakistan, droughts in Texas, heatwaves in Moscow and France, tropical storm Sandy, revolutions in Egypt and Syria have all been cited as evidence that we now can recognize some changes to the climate that are due to our actions.

However, apart from whatever contribution a drought in Syria might have made to their current civil war, the rest of those famously cited occurrences have disappeared from the conversation. This quite possibly means that some were too quick to seize on them as evidence of anthropogenically caused climate change. Perhaps it’s because the last few years haven’t thrown up more examples. Perhaps it’s because scientists who took the trouble to look at the record found that canicules in France and heatwaves in Moscow are not that unusual, that Pakistan’s floods were no stronger than seen in decades prior to 1945, that there is no global trend in drought and no national trend in U.S. heatwaves.

There is no doubt that the globe has warmed. It has warmed by 1 degree Celsius since 1880, more or less. I personally have little doubt that we have contributed significantly to that warming, via our CO2 emissions, deforestation and other land use changes. But to my mind there are remarkably few impacts extant from those changes. Even if human contributions to global warming added strength to the floods and storms, heatwaves and droughts that we have seen over the past decade, it hasn’t been enough to make those phenomena exceptional in any way.

Polar bears do not seem to be affected by the very real warming they have experienced.

polar_bear_pop (1)

Neither have coral reefs. Although more glaciers are receding than increasing, many of those in a state of decline started that decline long before we started to have an impact on our climate.

coral reefs

Diseases like malaria have decreased in range, while others such as dengue and now Zika are increasing. It’s possible that global warming has made larger sections of the world more hospitable to mosquitoes. It’s also possible that globalization has carried the mosquitoes along for the ride in luggage and clothing to more places than previously.

dengue

Many animals have moved polewards in response to warmer temperatures. But this is well-documented in almanacs from previous centuries. Lakes in North America are ice-free for larger percentages of the year. But that too has happened in the past.

IceCoverAvg1973_2015

What we can clearly recognize is a rise in global average temperatures, a modest rise in sea levels, lower summer minimums for Arctic ice–and what else?

Are there plausible changes to our environment and the species who inhabit it that we can note over the past few decades? I’d really like some help with this.

 

4 responses to “Recognizing a Changing Climate

  1. The mango trees planted in southern Spain are giving more, larger, better tasting mangoes. Cows are giving more milk in winter time.

  2. According to Richard Muller’s book, Energy for Future Presidents, about a third of BEST’s temperature stations have cooled over their lifetimes.

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