MELTING PERMAFROST

Ice sheets and glaciers located in Greenland and Antarctica are disappearing faster than expected.

This rapid decline in ice volume has triggered a positive feedback loop for additional warming and perpetuates sea-level rise.

•Liquid water in glaciers, together with the plant and microbial life it fosters, darken the ice and increase absorption of solar energy, which leads to further ice melt.

•In addition, scientists are discussing the impact of melting ice streams, which are located inside and under ice sheets, lubricating them and causing them to move more quickly into the sea.

Nearly half of the past century’s sea-level rise is attributed to thermal expansion – water expands when heated, so increased ocean heat means oceans are occupying more space.

•Thermal expansion is responsible for about 1.6 mm per year of sea-level rise.

•Projections show global sea-level rise could range from 0.2 to 2.5 meters by 2100.

RISING SEA LEVELS

THE ARCTIC HAS TRANSITIONS FROM A CARBON SINK TO A NET CARBON EMITTER

Melting Permafrost frees decaying biomatter that was trapped in the ice, cause the release of methane. Scientists have now discovered over 7,000 of these methane bubbles in Syberia.

The picture below is an exit crater caused by the methane explosion coming out after the land heated up and released it. Yamal Penisula, Siberia, 2014

The Arctic has become a greenhouse gas cont

RISING SEA LEVELS

With greenhouse gas emissions increasing and the planet warming, global mean sea-level rise is happening 25 percent faster than in the late twentieth century – with serious consequences for the planet.

•Researchers conclude that even if the strictest global emissions standards are met, sea levels would still rise from 0.7 to 1.2 meters within the next two centuries.

•Dozens of countries are exposed to the risk of coastal flooding caused by sea-level rise.

•Nearly one-third of the world’s population, or 2.4 billion people, live within 100 kilometers of a coastline, further emphasizing the vulnerabilities associated with increased sea-level rise.

Nearly half of the past century’s sea-level rise is attributed to thermal expansion – water expands when heated, so increased ocean heat means oceans are occupying more space.

•Thermal expansion is responsible for about 1.6 mm per year of sea-level rise.

•Projections show global sea-level rise could range from 0.2 to 2.5 meters by 2100.

REFERENCES:

[1*] The Maritime Executive, “Sea L2evel Rising Faster This Century,” April 26, 2017.

[2*] Josh Gabbatiss, “Global sea level to rise by up to 1.2 metres despite Paris agreement, say scientists,” Independent, February 20, 2018. https://www.independent.co.uk/environment/sea-level-rise-climate-change-paris-agreement-global-warming-greenhouse-gas-a8219681.html

[3*] National Aeronautics and Space Administration (NASA), “Living Ocean,” last updated July 2020. https://science.nasa.gov/earth-science/oceanography/living-ocean

[4*] National Oceanic Atmospheric Administration, “Is sea level rising?,” last accessed February 2020. https://oceanservice.noaa.gov/facts/sealevel.html

[5*] Christina Nunez, “Sea level rise, explained,” February 19, 2019. https://www.nationalgeographic.com/environment/global-warming/sea-level-rise/

[6*] Eli Kintisch, “The great Greenland meltdown,” Science Magazine, February 23, 2017. http://www.sciencemag.org/news/2017/02/great-greenland-meltdown

[7*] Rebecca Lindsey, “Climate Change: Global Sea Level,” National Oceanic and Atmospheric Administration, last updated November 19, 2019. https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level