By CHRISTINE FRANK
In a recent climate study published by James Hansen and 16 colleagues, the world was warned that two degrees of warming could lead to a rapid, catastrophic melting of land-based ice sheets and a sea-level rise of three meters or 10 feet in 50 years if fossil fuel combustion does not cease immediately. That large a rise in sea level would flood most coastal cities and render them uninhabitable, forcing millions of people to flee inland.
The report was released four months before the UN climate summit in Paris, where nations are to formulate a binding agreement to reduce greenhouse gas emissions to mitigate climate change, which is reaching runaway proportions.
Hansen and his team are convinced that the warming limit of two degrees Celsius, which was decided upon with no scientific basis whatsoever, is a formula for ecological disaster and economic collapse.
With warming of only 0.9 degrees Celsius above pre-industrial levels, there is already an enormous loss of the planet’s ice masses, with widespread effects on natural and human systems—weather, species behavior and biodiversity, food production, water resources, and health.
It is a crime to cultivate the delusion that we can adapt to climate change while continuing to burn hydrocarbons for the sake of convenience and the private profit of the Carbon Barons.
Low-lying, small-island nations have long demanded a one-degree Celsius limit, whereas, a total of 100 nations support a ceiling of 1.5. So then, what should it be?
Looking at paleoclimatic evidence from the warm interglacial period prior to this one, the researchers found that sea levels rose five to nine meters while the global temperature was less than one degree centigrade warmer than today. We must remember that the human climate forcing of fossil-fuel combustion is much stronger than that of the natural alterations in Earth’s orbit and axial tilt, which are what influenced the flux and flow of the great ice masses of the past.
The study also draws upon geological evidence in the Bahamas that powerful storms in the North Atlantic were caused by increased temperature, pressure, and moisture gradients as the planet warmed and the ice melted. In addition, a good deal of the paper focuses on how the Gulf Stream that warms Britain and Western Europe was shut down in ancient times due to the injection of freshwater from melting land ice that dramatically changed seawater salinity and affected the thermo-haline circulation of the ocean.
Both of these conditions could be repeated if Earth’s energy imbalance—more heat trapped by greenhouse gases, with consequently less being released into space—is not corrected soon.
The main thing to understand as we get close to the Paris summit is that greenhouse gas emissions have risen 2.6% per year since 2000, compared with 1.5% from 1973-2000. Turning the atmosphere into a waste dump for carbon pollution has led to carbon dioxide concentrations of 400 parts per million, over 40% more than pre-industrial levels.
When we consider that paleoclimate CO2 of 450 ppm was enough to melt most of Antarctica, and that current growth rates have more than doubled since the 1960s, we are perilously close to an irreversible cataclysm. That is why Hansen declared an overshoot several years ago when he maintained that atmospheric concentrations over 350 ppm are too high, hazardously so, and called for a drawdown to 350 or lower.
The world continues to feel the heat. Only nine months into 2015, it is safe to say that it will probably be the warmest year on record given the temperature records that have been broken around the globe so far. The El Nino will undoubtedly be adding to the trend. Temperatures have climbed steadily upward from 1950 to 2010, and there has been no hiatus or slowdown in warming over the last 15 years, as some have thought.
As far as the status of the cryosphere is concerned, all we need do is take a serious look at the present to see what the future will bring. New observations since the last IPCC report show the world’s ice masses in serious and irreversible decline. There has been a 50% loss in Arctic sea ice over the last decade. The 2015 winter maximum Arctic sea ice extent was the lowest on record in February and came 15 days earlier than usual. The lowest summer minimum was in 2012.
In the warm season, thick, old multi-year ice is being exported out of the region through the Fram Strait between northwest Greenland and Canada and into the Beaufort Gyre, where it meets its doom. Consequently, the North Polar ice cap has lost a tremendous amount of mass as it becomes increasingly thinner, younger, and vulnerable to melting.
A warmer Arctic is also having a strong influence on weather patterns in temperate regions because of the heat imbalance between the North Pole and the Equator, affecting the behavior of the Jet Stream and Polar Vortex. Most importantly, the dramatic loss of albedo or reflectivity due to there being less white ice and more dark water constitutes a positive feedback that is further warming the region and melting yet more ice.
Seasonal snow cover in the Northern Hemisphere, which has been below average for 10 years in a row, plays an important role in how much solar energy is reflected or absorbed. Snow cover reflects 90% of the sunlight that reaches it, whereas, snow-free land and dark ocean absorb so much more.
The timing of seasonal snow melt also affects the length of the growing season, the dynamics of spring river runoff, permafrost thawing, and wildlife populations. Evidence is emerging that over the long term, amplified warming of the Arctic is driving the rate of snow cover loss and other ecosystem responses. The rate of loss in the Northern Hemisphere has been 19.8% per decade, which exceeds the rate of summer sea ice loss.
The state of the permafrost is another serious matter. It comprises one quarter of the land in the Northern Hemisphere and stores massive amounts of carbon as CO2 and methane. The upper active layer that seasonally thaws has been growing with rising temperatures and losing its label “permanent.” As a result, coastlines are collapsing.
On Alaska’s North Slope, researchers found that 55% of the soil carbon floating in rivers is being oxidized into carbon dioxide as bacteria devour organic matter and belch CO2 . Methane is rising from lakes in plumes. On the continental shelves around the Arctic Circle, thawing methane hydrates are becoming increasingly unstable as sea ice melts, triggering unprecedented emissions from submarine sediments beneath the seafloor.
Russian scientists have found methane hotspots in the Laptev Sea, and over 250 plumes were seen rising near Spitsbergen due to a one-degree centigrade temperature increase in the current. In autumn, over the Eurasian and North American shelves, methane levels are between 20 and 25 parts per billion. The release of these greenhouse gases from the tundra and seabed are a positive feedback that can erupt into an enormous carbon bomb if things keep heating up.
Ordinarily, the Greenland Ice Sheet is frozen to its land base. However, rivers of melt-water are cutting walls and steep canyons into the ice, and water is plunging into moulins or sinkholes, causing the ice to slip from its moorings underneath and toward the sea. The volume of melt-water into the ocean from the Isortoq, a terrestrial river, is astonishing, over twice the flow of the Colorado River.
Superglacial lakes can also drain in hours, releasing up to 30 million cubic meters of freshwater to the sea. The continent is actively deglaciating. There has been a marked speed-up since 2010, with a 2-3% increase each summer in the acceleration rate.
Antarctica is another story. Although its sea ice extent has been increasing recently, it does not cancel out the losses in the Arctic Ocean, which are much greater than the gains around the South Pole. The increase in sea ice there is due to westerly winds in the Southern Hemisphere forcing the ice away from the continent, pushing the edges out, and creating spaces for more ice-making. This is occurring, ironically, because global warming has increased the temperature gradients between the pole and the Equator, making the westerlies stronger.
Also, the ozone hole over the region has had an impact. Normally, the ozone layer absorbs sunlight, which makes the stratosphere warmer, but now that the ozone is damaged and depleted, it makes the stratosphere colder and the area below as well.
The real problem facing the continent is the steady and rapid disintegration of the West Antarctic Ice Sheet (WAIS). Its two largest glaciers—the Pine Island and the Thwaite—are in trouble because the grounding lines that pin the ice shelves to the bedrock are below sea level. Warm seawater has been steadily eating away at the floating ice and its underpinnings. As the ice shelves lose mass and their buttresses erode, their ability to hold back the land-based glaciers, which are the source of sea-level rise, is greatly weakened. It is believed that the WAIS glaciers are past the point of no return since they have been speeding up for the last 40 years.
Because mountain peaks are warming faster than valleys and plains, alpine glaciers are in long-term retreat on every continent in every climate—temperate, tropical, and polar—a trend that became apparent in the 20th century. Several hundred of the world’s glaciers are losing between one-half and one meter of thickness per year, two times the average loss of the last century.
Glacier National Park had 150 of its namesake formations in 1850. The number has been reduced to 25, and Alaska is losing ice at the rate of 75 billion tons annually. The disappearance of mountain glaciers, which feed many of the major rivers of the world, has undermined the storage and timed release of water, threatening freshwater and food supplies. Moreover, the thawing of these land-based glaciers adds to sea level and accounts for one-third of its rise.
From paleo evidence, Hansen et al. conclude that sea-level rise came in pulses and occurred quickly and that ice sheets can melt at a non-linear rate—that is, exponentially, not incrementally—shedding enormous amounts of mass in decades rather than millennia, as the more conservative IPCC holds.
The UN panel has said that sea levels will rise three feet by 2100, a gross underestimation in comparison and a view long held in suspicion by others because existing climate models are underestimating the impacts of ice sheet melt. In contrast, Hansen believes that Greenland and Antarctica will melt 10 times faster than currently predicted.
The time of relatively stable climate since the last Ice Age is known as the Holocene, but because of powerful human influences on the climate, it has been labeled the Anthropocene by some. With the birth of agriculture and the clearing of forests for crops, humans were already influencing the climate 10,000 years ago. With the intensification of capitalist industrialization and mechanized warfare at the beginning of the 20th century, that process became even more intense. That is why Hansen now refers to the present as the Hyper-Anthropocene, and he believes that the very fabric of civilization will be torn to pieces if a serious and concerted effort is not made to meet this planetary crisis head on.
Unfortunately, Hansen’s solutions are still on the weak side, demanding the mild reform of a carbon fee or tax, although we would not object to taxing polluters clean out of existence if it were possible. His call for nuclear reactors powered by thorium are completely unacceptable as well.
The only way to stop further environmental devastation by a greedy capitalist class that refuses to give up its fossil-fuel-based economy is to nationalize the entire energy industry and put it under democratic workers’ control. At the same time, we must ensure a just transition with retraining, union wages, and full benefits for all workers making the shift from the production of dirty fuels to clean, renewable energy.
There is not one capitalist politician who supports such sweeping change. In fact, every short-sighted, self-serving vote hustler running in the elections this year is for maintenance of the status quo because their interests are tied hand and foot to the Energy Giants. That is why climate crisis activists and those struggling against environmental racism in their communities and on tribal lands must take their protests to the streets.
We must create a powerful movement for ecological and social change, and one of the best ways to do that is to build on the momentum of the People’s Climate March of last year and organize huge mass demonstrations demanding real action to cut greenhouse gas emissions from all sources to zero as soon as possible.
Plans for protests are already underway in many parts of the world leading up to the November-December climate talks, and we encourage all those wanting to save Mother Earth for human habitation and future generations to dedicate themselves to that effort.
