How is climate change affecting the Arctic Ocean?

Global warming is causing Arctic ice to melt – ice reflects sunlight, while water absorbs it. When the Arctic ice melts, the oceans around it absorb more sunlight and heat up, making the world warmer as a result.

Why is Arctic sea ice melting?

As water and air temperatures rise each summer near the Poles, some sea ice melts. Differences in geography and climate cause Antarctic sea ice to melt more completely in the summer than Arctic sea ice. ... For ice to thicken, the ocean must lose heat to the atmosphere. But the ice also insulates the ocean like a blanket.

Global warming is causing Arctic ice to melt – ice reflects sunlight, while water absorbs it.

For ice to thicken, the ocean must lose heat to the atmosphere.



Solar Radiation Management (sun dimming) uses various methods for reflecting the sun away from the earth .[Picture above taken May 12, 2017 by jt]

Does global warming cause ice age?

Although loosely based on science, the deep-freeze scenario is wildly implausible and scientists queued up to pour cold water on it. “It is safe to say that global warming will not lead to the onset of a new ice age,” two distinguished climate scientists wrote in the journal Science. Mar 14, 2018

 In 1959 there was discussions about deflecting the warm waters of the Japanese current by building a barrier near Bering Strait, thus sending part of the current into the Arctic basin and warming up polar regions to open them for habitation. Scientists pointed out that until meteorological knowledge  of the natural controls of weather and climate was more adequate it would be folly to undertake such a major change in ocean currents and climate because present knowledge indicated that warming of the Arctic ocean would set off a sequence of changes that would bring on another ice age.

In the South China Sea (SCS) between 2013 and 2017, China built 3,200 acres of new land, Vietnam built 120 acres of new land, and Taiwan built eight acres of new land. Given this level of activity in the SCS and the fact that environmental alterations,it's natural to ask: what impact do these activities have on  climate change?

Geoengineering refers to a set of emerging technologies that could manipulate the environment and partially offset some of the impacts of climate change. Solar geoengineering in particular could not be a replacement for reducing emissions (mitigation) or coping with a changing climate (adaptation); yet, it could supplement these efforts.



Carbon geoengineering seeks to remove carbon dioxide from the atmosphere, which would address the root cause of climate change — the accumulation of carbon dioxide in the atmosphere. In the chain from emissions to concentrations to temperatures to impacts, it breaks the link from emissions to concentrations.

Solar geoengineering seeks to reflect a small fraction of sunlight back into space or increase the amount of solar radiation that escapes back into space to cool the planet. In contrast to carbon geoengineering, solar geoengineering does not address the root cause of climate change. It instead aims to break the link from concentrations to temperatures, thereby reducing some climate damages.

There are several proposed solar geoengineering technologies. These include marine cloud brightening, cirrus cloud thinning, space-based techniques, and stratospheric aerosol scattering, amongst others.

Marine cloud brightening would attempt to brighten marine clouds to reflect more sunlight back into space.

Cirrus cloud thinning would attempt to reduce the thin, high-altitude cirrus clouds to emit more long-wave radiation from the earth to space.

Space-based technologies would attempt to reflect a small fraction of sunlight away from the earth by positioning sun shields in space.

Lastly, stratospheric aerosol scattering would introduce tiny reflective particles, such as sulfate aerosols or perhaps calcium carbonate, into the upper atmosphere, where they could scatter a small fraction of sunlight back into space.

More information can be found on the Technology Factsheet: Solar Geoengineering from the Harvard Belfer Center and Center for Research on Computation and Society (CRCS).

Climate models have consistently shown that solar geoengineering, when used in moderation and combined with emissions cuts, has the potential to reduce climate changes around the globe. For example, it could reduce climate impacts such as extreme temperatures, changes in water availability, and intensity of tropical storms.

However, any benefits come with novel risks and significant uncertainty. For example, while the latest science might show some benefits globally, local impacts could vary more widely. There are a lot of other scientific uncertainties that are not yet well understood, not least the enormous governance challenges.

Also, solar geoengineering (largely) does not address ocean acidification. Every year, the ocean absorbs about one-quarter of the carbon dioxide we emit into the atmosphere, changing the chemistry of the oceans and harming marine ecosystems. Given that solar geoengineering would not remove carbon dioxide from the atmosphere directly, but rather reflect sunlight back to space, it could do little to address this serious problem except via carbon cycle feedbacks, the process through which additional carbon is emitted into the atmosphere upon additional warming.

That said, solar geoengineering could reduce rising temperatures, offsetting many impacts on the oceans. For example, by reducing sea surface temperatures, it could reduce the risk of coral bleaching events and help to maintain conditions favorable for coral reefs (as the damage to coral reefs is largely caused by rising sea surface temperatures, followed by intensifying ocean acidification). Solar geoengineering could also reduce poleward shifts in species ranges, which has been posing serious risks to tropical fisheries. And it could lessen the amount of sea-ice loss, which could reduce the impacts on high-latitude ecosystems and climate, and help to limit changes in ocean circulation and glacier melt.

In any case, solar geoengineering could not be a substitute for cutting carbon dioxide pollution. It could only be a potential supplement.

Research could reduce uncertainty about the technology’s potential benefits and risks, but, for decades, research in solar geoengineering has been limited. This has been in part because of a fear that it could lesson efforts to cut emissions. There have also been concerns pertaining to its ethics, governance, and potential impacts to the climate system. Recently the U.S. National Academy of Sciences and major environmental groups such as the Environmental Defense Fund and the Natural Resources Defense Council have begun to support careful research. The U.S. also published the Climate Science Special Report, which discussed geoengineering and called for further research. The report was a key part of the Fourth National Climate Assessment, which the U.S. Global Change Research Program (USGCRP) oversaw.

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