Because of global warming, permafrost — the frozen ground that covers the top of the world — has been thawing rapidly over the last three decades. But there is cause for concern beyond the far north, because the carbon released from thawing permafrost could raise global temperatures even higher.
In the past century, as the climate has warmed, sea level rise has accelerated. Scientists predict it will only increase, and they’re studying changes in the ocean and land to better understand how and why the water is rising.
Coupled Processes in the Arctic System: Feedbacks, Amplification, and Impacts on Midlatitudes I
Wednesday Room 104, 10:20 AM
Jennifer Francis presentation begins at 1hr and 51 min. and goes on for about 15 min. Click on the picture to connect to the video. Allow it to “load” a bit, and then move the slider to the point of 1hr. 51 min. to view her presentation.
One of the most pronounced effects of climate change has been melting of masses of ice around the world. Glaciers and ice sheets are large, slow-moving assemblages of ice that cover about 10% of the world’s land area and exist on every continent except Australia. They are the world’s largest reservoir of fresh water, holding approximately 75% (1). Over the past century, most of the world’s mountain glaciers and the ice sheets in both Greenland and Antarctica have lost mass. Retreat of this ice occurs when the mass balance (the difference between accumulation of ice in the winter versus ablation or melting in the summer) is negative such that more ice melts each year than is replaced (2). By affecting the temperature and precipitation of a particular area, both of which are key factors in the ability of a glacier to replenish its volume of ice, climate change affects the mass balance of glaciers and ice sheets. When the temperature exceeds a particular level or warm temperatures last for a long enough period, and/or there is insufficient precipitation, glaciers and ice sheets will lose mass. One of the best-documented examples of glacial retreat has been on Mount Kilimanjaro in Africa. It is the tallest peak on the continent, and so, despite being located in the tropics, it is high enough so that glacial ice has been present for at least many centuries. However, over the past century, the volume of Mount Kilimanjaro’s glacial ice has decreased by about 80% (3). If this rate of loss continues, its glaciers will likely disappear within the next decade (4). Similar glacial meltbacks are occurring in Alaska, the Himalayas, and the Andes.
Conclusion As CO2 emissions and climate change continue, risks to the health of the ocean will become a more prominent concern. With accelerated melting back of glaciers and ice sheets and the subsequent rise in sea level, with further decreases in oceanic pH, and with deceleration of the thermohaline circulation, there are many ways in which the delicate balance of ocean dynamics and ecosystems are being put at risk. These factors, combined with the uncertainty in predicting exactly how these impacts will interact, are causing changes in the ocean: an increasingly problematic issue for future generations
Environmentalist Dan Miller discusses images of arctic ice melting trends at the North Pole. He argues that light once reflected off the surface of the melting ice is now being absorbed by water, priming a feedback loop that will continuously accelerate the melting process.
The world’s glaciers are shrinking at alarming rates, and many scientists believe it is due to changes in climate. Dr. Lonnie Thompson of Ohio State University and Dr. Douglas Hardy of UMass-Amherst discuss glaciers and how they melt, and pay special attention to Africa’s tallest mountain, Mt. Kilimanjaro.
Welcome to Transition Studies. To prosper for very much longer on the changing Earth humankind will need to move beyond its current fossil-fueled civilization toward one that is sustained on recycled materials and renewable energy. This is not a trivial shift. It will require a major transition in all aspects of our lives.
This weblog explores the transition to a sustainable future on our finite planet. It provides links to current news, key documents from government sources and non-governmental organizations, as well as video documentaries about climate change, environmental ethics and environmental justice concerns.
The links are listed here to be used in whatever manner they may be helpful in public information campaigns, course preparation, teaching, letter-writing, lectures, class presentations, policy discussions, article writing, civic or Congressional hearings and citizen action campaigns, etc. For further information on this blog see: About this weblog. and How to use this weblog.
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