If Antarctica joins in and starts to melt in the summer as well, the rate of global-sea level rise will really go up fast and that will be a big impact on countries like Bangladesh, which are low-lying and kind of helpless in the face of sea level rise.

Welcome, caring viewers, to the concluding episode of our two-part program on the quickly melting polar ice caps featuring a discussion with Professor Peter Wadhams who is the Professor of Ocean Physics at the Department of Applied Mathematics and Theoretical Physics at Cambridge University, UK.

I specialize in the study of sea ice and I run a research group which works on the thickness and properties of sea ice, and the motion of sea ice and at the moment, of course, the climatic effects of sea ice, the fact that it’s disappearing. So that involves working in the Arctic and in the Antarctic, using underwater vehicles to measure how the (ice) thickness is changing.

This week, in addition to addressing the precarious state of the Arctic and Antarctic, Professor Wadhams speaks about accelerating climate change and the serious threats to the future of civilization posed by sea level rise.

In 2009 the United Nations Climate Change Conference, or COP 15, took place in Copenhagen, Denmark. The participants agreed that it is absolutely vital to limit the Earth’s temperature increase to two degrees Celsius or less. Climate scientists say that if this point is exceeded, catastrophic events such as a loss of up to 30% of the world’s plants and animals are projected to eventually occur. Professor Wadhams says we’ve already entered this extreme danger zone.

The hope that global temperatures on average could be held to a two-degree (Celsius) rise has already passed. That was the crazy thing about the Copenhagen Agreement, that you should restrict the rise to two degrees. It was already at two degrees. So, the idea that the world could be held to a rise (of two degrees), which had in fact already happened, was ludicrous.

But the average predictions, for instance, for Europe are about four degrees (Celsius) of warming by the end of this century. And Britain being a bit lower, about two degrees because of the cooling effect of the Atlantic and the decline of the Gulf Stream. About four degrees for a region like the Mediterranean coast of Europe means that you’re converting the Mediterranean coast of Europe into the equivalent of North Africa.

You’re shifting climate zones, and four degrees all over the world is going to have similar big impacts everywhere. And that’s an average prediction based on the “business as usual” idea that we will keep on increasing our CO2 levels at roughly the same rate.

And of course, the optimistic hope is that we will reduce CO2levels, but in fact, the last few years we’ve been increasing them at more than the “business as usual” rate. The rate of increase has itself risen, so we’re doing worse than expected. We’re going into a worst-case scenario; we’re doing worse than nothing. And so we may well get warming that’s more than say four degrees by the end of the century.

If it’s five or six degrees (Celsius), in the Arctic it will be 10 or 12 degrees (Celsius), because there’s an amplifying factor of about two, and that will really be enough to have serious effects on both sea ice and land ice, and change the whole environment of the Arctic and the Antarctic. Around the coast of Greenland and the Antarctic you’re seeing a speeding up of the flow rate of glaciers that are flowing out to sea, and they’re carving off more icebergs.

If we’re thinking about runaway climate change, it might happen as far as something like the Arctic sea ice is concerned. Some features of the Earth’s surface could disappear permanently. The Sahara (Desert) could grow enormously in area. So in that sense you might get a runaway effect.

Low-lying island nations such as the Tuvalu and Kiribati in the South Pacific face the possibility of soon being submerged under the sea and their leaders have asked other nations to help them resettle their populations. Already a fifth of Tuvalu’s people have immigrated to New Zealand. However, without quick action, the rest of the world may soon feel the effects of higher waters to the same degree.

And so we think we’re in a bad way in Europe, but they’re in a much worse way in Asia from sea level rise. And that’s probably the most immediate and nastiest impact of global warming, global sea levels, especially around the coasts of poor countries. It’s the statistics of extremes; if you have a distribution of heights above normal sea level, it’s called a “bell-shaped curve,” but if you move the mean up a bit, the probability of getting some disastrous amount above the mean is greatly increased.

The melting of the Greenland ice sheet, which is part of the Arctic, is one of the main drivers of sea level rise and is of deep concern to climate researchers worldwide.

The Southern Greenland coast is still ice-free, which is very unusual. And that means that you’re getting a lot of evaporation from the ocean. You’re getting warm winds coming in over Greenland. And whenever you get sea ice retreating around Greenland, it tends to speed up the rate of loss from the ice sheet. And at the moment I don’t think the effect will be to destabilize the Greenland ice sheet in the short term, but there’s a big effect on sea level.

And at the moment about half the global, rising sea level is due to warming of the ocean and the other half is due to melting of ice from glaciers. Up to now it’s been mostly glaciers in mountains, low latitudes, (Mt.) Kilimanjaro and so on, but in the last few years the Greenland ice sheet has started to melt in the summer.

And the amount of melt that’s going on now is about half of the total from everything else, so suddenly the Greenland ice sheet is a major player in contributing to global sea level rise. And that can only get worse.

Moulins are burrows or tubular shafts in a glacier that allow running water to flow through from the surface to the bottom. These openings can be hundreds of meters deep, depending on the size of the glacier or ice sheet. These shafts are appearing in the Greenland ice sheet and are a warning signal we are fast losing a key part of the Arctic. If this ice sheet were to disintegrate entirely, scientists say it would raise sea levels by a staggering seven meters.

What seems to be happening in Greenland is that you never used to get surface melt on the ice sheet in summer, but now you do. The melt water finds holes, called moulins, through which it rushes down to the bedrock level and lubricates the bedrock, so that the bed of the glaciers flows faster. And then you’re getting more rapid flow of glaciers out to sea giving off more icebergs.

At the moment, many of the glaciers in Greenland are now flowing twice as fast as they did 10 years ago. It’s just producing more icebergs and it’s increasing the rate of loss from the ice sheet.

The situation in the Antarctic is grave as well, with the ice there disappearing at a rapid rate. A report in the journal Science states that the collapse of the West Antarctic Ice Sheet can produce an effect on the Earth’s spin great enough to cause the planet’s axis to shift as much as 500 meters. This alarming discovery was made by a scientific team from the Earth System Evolution program of the Canadian Institute for Advanced Research.

Other analysts have predicted that if this ice sheet collapses, sea level rise will be as high as five meters. However, the Canadian research team reasons that this prediction was based on oversimplified measurements that only involved the volume of the ice sheet and its associated water amount.

The new research on the West Antarctic Ice Sheet has found that its melting would cause more severe consequences due to reduced gravitational effects on the ocean from melting ice sheets, and would thus upset Earth’s balance. As a result, massive amounts of water would shift from one area to another. According to the report, “Water would migrate from the southern Atlantic and Pacific Oceans northward toward North America and into the southern Indian Ocean.”

One of the researchers involved in the new study is geophysicist Dr. Jerry Mitrovica, who states, “The net effect of all of these processes is that if the West Antarctic Ice Sheet collapses, the rise in sea levels around many coastal regions will be as much as 25% more than expected, for a total of between six and seven meters if the whole ice sheet melts.”

The fastest and easiest way to address climate change and its dire consequences, only some of which have been briefly covered today, is through a worldwide change to the planet-cooling, plant-based diet. Professor Wadhams too believes that what we choose to eat makes a tremendous difference.

When you’ve got so many people who are switching from one system to another, the change is enormous. So, if people ate less meat, you would have an impact on the amount of land used for looking after domestic animals. Instead you could grow food directly.

That would reduce the amount of methane being emitted, which would have an impact on the rate of global warming. You’d also be increasing the sheer amount of vegetation, which would be improving the way in which carbon dioxide is absorbed by the earth system. So it would be very good in lots of different ways.

Once again our appreciation Professor Peter Wadhams for your clear explanation of the many dangers our planet is facing. May the invaluable information on the state of the Arctic and Antarctic as well as our Earth’s climate you are disseminating continue to remind us all of our need to take urgent action on global warming.

For more details on Professor Peter Wadhams, please visit www.DAMTP.cam.ac.uk/people/p.wadhams

Thank you for your company today on Planet Earth: Our Loving Home. May we all soon create a world vegan community for world peace and planetary stability.