“Shrinking ice caps forced National Geographic to make the biggest change in its atlas since the Soviet Union broke apart.”
A series of semaphores I’ve come across on climate change in the last few weeks and months put me in the mind of collecting a few into a blog post. Many of them were moving maps which showed clearly the climate-change strikes against us. This map, for example, that Obama was speaking of:
Sea levels can rise in two ways: by warming and resulting expansion, and by increased volumes when ice caps melt. Melting ice caps could account for a third of rising sea levels. Here’s how the ice and rising temperatures play with each other:
Ice loss is accelerated in the Arctic because of a phenomenon known as the feedback loop: Thin ice is less reflective than thick ice, allowing more sunlight to be absorbed by the ocean, which in turn weakens the ice and warms the ocean even more, NASA says.
Because thinner ice is flatter, it allows melt ponds to accumulate on the surface, reducing the reflectiveness of the ice and absorbing more heat.
The latest data from the source the mappers reference, the National Snow & Ice Data Center, does not sound good.
While Arctic sea ice retreated at near average rates during the month of June, the pace of ice loss quickened in July such that the extent at the end of the month was within 550,000 square kilometers (212,000 square miles) of the extent recorded on the same date in 2012, and is now tracking below 2013 and 2014.
Although the pace of ice loss is almost always faster in July than in June, the July rate of loss for 2015 has been pronounced. The rate of ice loss for July 2015 averaged 101,800 square kilometers (39,300 square miles) per day, compared to 97,400 square kilometers (37,600 square miles) in 2012 and 86,900 square kilometers (33,500 square miles) per day in the long-term 1981 to 2010 average. This rapid loss is in part a result of fairly high air temperatures over most of the Arctic Ocean.
See what would happen if all the ice at the polar caps melted, in this interactive map from National Geographic. By the way, the National Geographic News website says that the Arctic ice caps melted further after September last year, when this atlas was published.
High July 2015 temperatures have given the month the dubious distinction of being the hottest July on record. And all that heat is being absorbed by oceans, warming them up at a rate much faster than expected. Climate Central reports:
Durack and Lawrence Livermore colleagues worked with a Jet Propulsion Laboratory scientist to compare ocean observations with ocean models. They concluded that the upper levels of the planet’s oceans — those of the northern and southern hemispheres combined — had been warming during several decades prior to 2005 at rates that were 24 to 58 percent faster than had previously been realized.
In a season for climate superlatives in the United States, researchers and weather watchers are calling this El Niño year the “strongest” on record. This report based on NASA’s data has charted the temperature rise and concluded that 2015 might yet be the hottest year ever “crushing” the previous hottest year, 2014, “by a wide margin.” Some of the fiercest wildfires rage across the American west (do look at this for a sense of how the frequency of “megafires” have increased in the recent decades), and for Alaska this has proved to be “one of the worst wildfires seasons in history.”
On May 6, 2015, humankind achieved yet another (notorious) milestone in climate terms this year, with the global average concentration of carbon dioxide reaching 400 parts per million (ppm) for the first time in history.
The International Energy Agency reported on March 13 that the growth of global emissions from fossil fuel burning stalled in 2014, remaining at the same levels as 2013. Stabilizing the rate of emissions is not enough to avert climate change, however. NOAA data show that the average growth rate of carbon dioxide concentration in the atmosphere from 2012 to 2014 was 2.25 ppm per year, the highest ever recorded over three consecutive years.
Scientists widely hold that we need to revert to no more than a global average of 350 ppm to stabilize the climate system. The last time global concentrations were this high was millions of years ago, when humans did not exist. The rising CO2 in the air could have dire implications for food security and biodiversity, especially in the tropics.
Nowhere to go
While the melting ice caps, bemused polar bears, crashing icebergs, and glaciers running thinly blue are visual alarms of rising temperatures, the tropics may be facing a far quieter, more sinister danger. Why? Species of the tropics are not used to wild fluctuations in summer/winter temperatures that the arctic regions see. As a result, they may be more thermally sensitive and even small changes in temperature could affect them adversely.
In a 2011 article in Yale 360, William Laurance writes:
In the tropics, the key temperature gradient is associated with elevation. For every thousand meters you go up in elevation, the temperature drops by an average of 6 degrees C (11 degrees F). For this reason, many tropical species exist not just in a narrow temperature range, but at defined elevations. Some creatures are confined to the hot lowlands. Others live at mid-elevations. And still others are specialized for cool, cloudy mountaintops.
There is the oft-quoted astounding and telling observation of the Australian biologist Justin Welbergen who saw flying foxes — the largest bats in the world — drop dead when the mercury soared to 42 degrees Celsius. It is not just creatures that are feeling the heat. Trees feel it too and — believe it or not — tropical trees are migrating up the mountains in search of cooler climes, as this research by Kenneth J. Feeley shows us.
Mountains are home to some of the rarest and highest concentrations of endemic species in the world. When the mercury climbs, where will species that live on mountain tops go?
So, what does this mean for us?
The climate system is dynamic and complex and to peg any one catastrophic event on it alone is impossible, even erroneous. But research across disciplines — biology, paleontology, meteorology, oceanography, zoology, and anthropology all converges to point out trends that have us in uncharted territory. Never have temperatures been this high, never has there been as much CO2 in the atmosphere.
While trees migrating and species moving up mountains may sound far removed from our daily lives, they really are not. They are reactions to changes in climate that are affecting us as well: in failed crops and unpredictable rainfall patterns, in increased frequency and intensity of droughts and floods and wildfires, in extremes of cold and heat waves, in famines and dried-up aquifers, in violence born of starvation, homelessness, and inequity.
Is this the writing on the wall?
Mene, mene, tekel, upharsin.
I’ll leave you with a book that has set me thinking. In Tropic of Chaos, Christian Parenti takes us on a journey across the world and shows us how climate change could exacerbate underlying social, environmental, and economic inequities, painting us a world of implications for the anthropocene.
Climate change arrives in a world primed for crisis. The current and impending dislocations of climate change intersect with the already-existing crises of poverty and violence. I call this collision of political, economic, and environmental disasters the catastrophic convergence. By catastrophic convergence, I do not merely mean that several disasters happen simultaneously, one problem atop another. Rather, I argue that problems compound and amplify each other, one expressing itself through another.
Parenti, Christian (2011-06-28). Tropic of Chaos: Climate Change and the New Geography of Violence (p. 7). Nation Books.