“ Unfavorable and involuntary consequences ”: polar geoengineering is not the response to climate change
Our planet continues to warm up because of greenhouse gas emissions human activities. Polar regions are particularly vulnerable to this warming. The extent of sea ice is already down in both Arctic And Antarctic. The Greenland and Antarctic Greenland caps melting, and sudden changes In both polar environments, are underway.
These changes have significant implications for society by raising sea level, changes in ocean circulation and climatic extremes. They also have substantial consequences for polar ecosystems, including polar bears and emperor penguins, which have become emblematic symbols of the impacts climate change.
The most effective way to alleviate these changes and reduce the risk of generalized impacts is to reduce greenhouse gas emissions. However, decarbonization is slow and current projections suggest that the temperature increases in About 3 ° C per 2100.
Given the expected change and the importance of polar regions for planetary health, some scientists and engineers have proposed technological approaches, called geo-engineers, to soften the blow of the Arctic and the Antarctic.
In research Published today in Frontiers in Science, my colleagues and I have evaluated five of the most developed geo-engineering concepts envisaged for the polar regions. We found that none of them should be used in the coming decades. It is unlikely that they will reduce the effects of global warming in polar regions and are likely to have serious unfavorable and involuntary consequences.
What is polar geo-engineering?
Geo-engineering encompasses a wide range of ideas for large-scale deliberate attempts to modify the climate of the earth. THE Two widest classes Involve the removal of carbon dioxide from the atmosphere and the increase in the amount of sunshine reflected in space (called “modification of solar radiation”).
For polar regions, here are the five most developed concepts.
Stratospheric aerosol injection is an approach to modify solar radiation which involves the introduction of finer particles (such as sulfur dioxide or titanium dioxide) in the stratosphere to reflect sunlight in space. In this case, the emphasis is specifically placed on the polar regions.
Sea curtains Are flexible, floating structures rooted at the seabed 700 meters to 1,000 m deep and up 150 m to 500 m. The objective is to prevent hot water from the ocean from reaching and melting the ice shelves (floating ice extensions which slow down the movement of the Greenland and Antarctic ice in the ocean) and the spare lines of ice caps (where the earth, the ice cap and the ocean meet).
Sea Ice Management Includes two concepts. The first is the diffusion of glass microbeads on the Arctic fresh sea ice to make it more reflective and help it survive longer. The second pumping sea water on the surface of the sea ice, where it will freeze, in order to thicken the ice – or in the air to produce snow, with the same general effect, using wind pumps.
Elimination of basal water Target the ice flows found in the glacial caps of Antarctica and Greenland. These streams are ice rivers that quickly move towards the coast, where they can enter the ocean and raise sea level. Water at their base acts like a lubricant. This concept proposes to eliminate the water from their base to increase friction and slow down the flow. It is believed that the concept is particularly relevant for Antarctica, which has much less surface melting than Greenland, and therefore the cast iron concerns the base of the ice cap than its surface.
Ocean fertilization Implies the addition of nutrients such as iron with polar oceans to promote the growth of phytoplankton. These tiny creatures absorb carbon dioxide from the atmosphere, which is stored in the deep ocean when they die and flow.
The risk of false hopes
In our research, we have evaluated each of these concepts against six criteria. These included: range of implementation; feasibility; financial costs; efficiency; environmental risks; and governance challenges.
This framework offers an objective means of assessing all these concepts for their merits.
None of the concepts of proposed polar geo-engineering has managed to examine the concepts that are achievable in the coming decades. The criteria that we have used show that each of the concepts faces several difficulties.
For example, to cover 10% of the Arctic Ocean with pumps to deliver sea water to freeze within ten years, one million pumps per year should be deployed. THE Estimated costs Sea curtains ($ 1 billion per kilometer) are underestimated by similar-scale projects in easier environments, such as the Thames barrier near London, from six to 25 times.
A project This planned to spread glass microbeads on the ice has also been closed by citing environmental risks. And during their last meeting, the majority of the advisory parties of the Antarctic Treaty clear Their opinion that geo-engineering must not be carried out in the region.
The proposals of polar geo-engineering raise false hopes to avoid certain disastrous consequences of climate change without quickly reducing greenhouse gas emissions.
They risk encourage complacency on the urgency of making zero net emissions by 2050 or may be used by powerful actors as an excuse to justify continuous emissions.
The climate crisis is a crisis. During the time available, efforts are better focused on decarbonization. The advantages are quickly short -term.
This published article is republished from The conversation Under a creative communs license. Read it original article.
