Landscape architect Kristina Hill focuses on helping cities adapt to climate change, particularly sea level rise. In an interview with Yale Environment 360, she discusses the challenges, solutions, and costs of saving cities from encroaching oceans.

One of the thorniest questions facing climate scientists is whether human-induced climate change is leading to more heat waves, floods, and extreme weather events. Now, employing increasingly sophisticated methods of studying weather extremes, climatologists say they are closer to answering that key question.

Forecasting what the Earth’s climate might look like a century from now has long presented a huge challenge to climate scientists. But better understanding of the climate system, improved observations of the current climate, and rapidly improving computing power are slowly leading to more reliable methods.

The fringes of the coldest continent are starting to feel the heat, with the northern Antarctic Peninsula warming faster than virtually any place on Earth. These rapidly rising temperatures represent the first breach in the enormous frozen dome that holds 90 percent of the world’s ice.

Unearthing photographs of the Himalaya dating back more than a century, mountaineer and filmmaker David Breashears has assembled a powerful visual record of the rapid retreat of the region’s glaciers. By comparing archival photographs from such renowned explorers as George Mallory to photographs taken in the past three years, Breashears has documented the steady disappearance of these great rivers of ice, whose melting will eventually threaten the water supplies of hundreds of millions of people across Asia.

As the world warms, sea levels could easily rise three to six feet this century. But increases will vary widely by region, with prevailing winds, powerful ocean currents, and even the gravitational pull of the polar ice sheets determining whether some coastal areas will be inundated while others stay dry.

The shrinking ice cap atop Mount Kilimanjaro is Africa’s most famous glacier. But the continent harbors other pockets of ice, most notably in the Rwenzori Mountains of western Uganda. And as temperatures rise, the Rwenzori’s tropical glaciers — located as high as 16,500 feet — are fast disappearing.

Living on shifting land formed by river deltas, the people of Bangladesh have a tenuous hold on their environment, with cyclones buffeting coastal zones and rising seas posing a looming threat. But, as this Yale Environment 360 video report by Jonathan Bjerg Møller makes clear, many Bangladeshis already are suffering as a growing population occupies increasingly vulnerable lands.

As governments, businesses, and homeowners plan for the future, they should assume that the world’s oceans will rise by at least two meters — roughly seven feet — this century. But far too few agencies or individuals are preparing for the inevitable increase in sea level that will take place as polar ice sheets melt.

The treeless ecosystem of mosses, lichens, and berry plants is giving way to shrub land and boreal forest. As scientists study the transformation, they are discovering that major warming-related events, including fires and the collapse of slopes due to melting permafrost, are leading to the loss of tundra in the Arctic.

On the eve of the Copenhagen conference, a group of scientists has issued an update on the 2007 report of the Intergovernmental Panel on Climate Change. Their conclusions? Ice at both poles is melting faster than predicted, the claims of recent global cooling are wrong, and world leaders must act fast if steep temperature rises are to be avoided.

As the world warms, how different societies fare in dealing with rising seas and changing weather patterns will have as much to do with political, social, and economic factors as with a changing climate.

Amid a growing call for reducing atmospheric concentrations of CO2 to 350 parts per million, a group of economists maintains that striving to meet that target is a smart investment — and the best insurance policy humanity could buy.