Our Changing Climate

“Oh, East is East, and West is West, and never the twain shall meet...”

How things have changed in the world since Rudyard Kipling wrote those words—even high above the Indian subcontinent, birthplace of the celebrated author and poet.

There, east and west likely met throughout the 1950s and ‘60s, in the form of radioactive fallout from the testing of atomic weapons in places like Nevada. Scientists know winds carried that fallout around the world before it eventually settled out of the atmosphere, including onto the ice that drapes much of the Himalayas.

In fact, researchers who drill into glaciers and ice fields around the globe have long and reliably turned up traces of that radioactivity, typically finding it buried beneath the snow and ice piled on in the years since A-bomb testing ceased. The strontium 90, cesium 136, and other isotopes have provided those experts with a clever way of dating their core samples—an atomic-age benchmark, if you will. Since the ice sullied by the radioactivity must date to the era of atmospheric testing, everything above that level had to have accumulated in the years and decades since, and in depths and volumes that are measurable.

But scientists who recently drilled into an ice field high in the Himalayas came up empty-handed, at least when it came to finding similar benchmarks. A joint U.S.-Chinese team last year pulled four ice core samples from the summit of Naimona'nyi, a large glacier 6,050 meters (19,849 feet) high on the Tibetan Plateau. But none contained any trace of the radioactivity found in virtually every other ice core extracted worldwide.

Was the glacier never dusted with radioactive fallout? Unlikely. Instead, any isotope-sprinkled layer of ice probably melted away sometime in the last 50 years. That means the Tibetan ice field is shrinking—and probably has been for quite some time, scientists reported in their findings at the fall meeting of the American Geophysical Union in San Francisco, California.

That’s bad news for one in six people on Earth, as the largest concentration of ice outside the polar caps is locked in the Himalayas. Glacial melt from the region feeds the Ganges, Indus, Mekong, Yangtze, and other major rivers, which roughly a billion people in China, India, Nepal, and other countries rely on.

While melting glaciers mean an abundance of water in the short term, eventually they will shrink away to nothing. When that happens, the flood will turn to a trickle — and choke off the water supply for a large chunk of the world.

In our personal lives, we often use the end of one year and the beginning of the next to take stock of where we’ve been and where we’re heading. Scientists do, too.

According to findings released this week by Dr. James Hansen, director of the NASA Goddard Institute for Space Study, last year’s global mean temperature kept up the current trend of being about 0.6º C (1º F) warmer than the 1951-1980 mean.

What makes 2007 especially noteworthy, however, is that this warmth occurred in spite of natural cycles that periodically cool off Earth.

Solar irradiance was at its lowest point in an approximately 10-year cycle, and the Pacific Ocean entered the La Niña phase of the El Niño-Southern Oscillation. In other words, last year less solar radiation reached the earth and the waters of our planet’s largest ocean basin got a little colder--but the Earth got warmer anyway.

Nothing we’ve done lately alters these natural cycles. Rather, the problem is that now our activities are adding to the mix as well: human-caused warming from greenhouse gases has become so significant that it too can exert a mighty force—so much so that for the first time in Earth’s history, our behavior can actually override nature.

The reality is that in the past 100 years La Niña has come and gone and solar activity has risen and fallen many times, but the top five warmest years on record have all occurred in the last decade.

Indeed, if those naturally occurring cooling cycles were not happening it’s possible that 2007 would have turned out to be even warmer than it was.

Of course, although deeply disturbing, this latest news isn’t anything like a genuine surprise. Rather it’s just more evidence of what has already been detailed in countless studies.

The cascade of effects following from the Earth’s “fever”, such as rising sea levels, melting ice, changing weather patterns and habitat disruption, while scary and sad, isn’t particularly mystifying or astounding to scientists either. It’s simply the expected consequence of that temperature rise: the basic laws of nature virtually demand that if you warm up the planet, these things will occur.

Not to oversimplify too egregiously, but scientifically, this all pretty much just makes sense, in a 2+2=4, night-follows-day, sort of way. And while the accelerating pace of these changes may startle us, even this ever-quickening tempo—faster than anything predicted—doesn’t actually bewilder experts now that it’s happening.

So the truly grim take-home message abiding just beneath all these recent scientific findings is this: given how humanity barrels on, blindly conducting business as usual, perhaps the only thing that really would confuse and confound most scientists at this point is if current trends suddenly, somehow, reversed themselves.

Andrew is a science journalist and author who has written several books for Sally Ride Science, including Earth’s Precious Resources: Clean Air.

Will a teensy car that costs less cool cash when new than any other automobile in the world have an outsized impact on a warming planet? That’s the question on the mind of many environmentalists as India’s Tata Motors unveils its so-called People’s Car: a pint-sized auto with an even smaller price tag.

Costing a smidge over $2,500, Indian manufacturer Tata Motors says the car will be the world’s cheapest when it goes on sale later this year. It plans to build at least 250,000 of the cars annually.

That’s only a drop in the 50 million-unit-a-year global market for new vehicles. Still, it may herald a flood of similarly inexpensive cars that could put millions of people around the world behind the wheel for the first time.

There’s certainly the demand in places like India and China. In either nation, there are less than two dozen cars on the road for every 1,000 people. Compare that to the United States where vehicle ownership is about 700 per 1,000, and it’s clear why the Indian and Chinese automotive markets are hot.

It’s also clear that gasoline consumption—and emissions of greenhouse gases—will grow in India and China as more and more cars stream onto the thousands of miles of new roads hurriedly being built in both nations.

That raises the prospect that one day the two countries could be as awash in traffic as is the United States today. Granted, that could take decades: one study estimates it will take until 2030 to swell the global parking lot with 2 billion cars, up from 800 million in 2002.

But could the world supply the gasoline or diesel, at reasonable cost, needed to keep that many cars running? And could the world withstand the added carbon dioxide and other emissions pouring from that many more tailpipes?

It’s not clear. But it is important to remember that adding a new Tata on the road in Delhi isn’t the same as, say, putting a new Ford on the streets of Detroit—at least when it comes to fuel consumption and greenhouse gas emissions.

Tata’s new car is expected to come with a 660cc engine—that’s less than one-fifth the displacement of the 3.5 liter engine found in a Ford Edge. And sure, Tata drivers will have to be content with a horsepower rating that’s about one-eighth that of a new Edge, but they should be able to travel 50 or more miles on each gallon of gas.

That would make the Tata about half as thirsty as the Ford. Because of that, the Indian car should produce half the CO2 as its American counterpart for each mile it travels.

That means 250,000 Tata econo cars tooling around India will gobble about the same amount of gas and belch roughly the same amount of CO2 as the 130,000 Ford Edges sold in the U.S. last year (assuming each Ford and Tata travels the same distance and gets 25 and 50 miles per gallon, respectively, in doing so).

So is the debut of a car that could put driving within the reach of millions across the developing world genuine cause for environmental concern?

The answer’s a qualified yes since each new Tata, as fuel efficient as it may be, is just one more oil-consuming, pollution-producing car on planet Earth. But Tata may ratchet up the pressure on other automotive manufacturers to roll out other cars that are just as thrifty. Expanding and updating the world’s automotive fleet with more fuel-efficient models could help contain global demand for oil and keep tailpipe emissions in check—even as the number of vehicles on the road blossoms.

At least one car company already appears to get the message. Ford Motor Co. announced plans this month to produce a new compact car for one of the world’s fastest growing automotive markets—a country called India.

Laurie is a science and environmental journalist and author. She wrote the Sally Ride Science book Our Changing Climate: The Oceans.

I am very lucky that I have been able to spend so much of my life on or near the ocean. It’s always been my favorite place to be—no contest.

For nearly ten years I was part of a team of researchers studying the North Atlantic right whale. These giants are some of the most endangered animals in the world--they got their name because they were long considered the "right" whale to hunt. Despite more than 60 years of protection, there are still only about three hundred of them left in the entire North Atlantic. Every year, in the deepest part of the winter, a sizable portion of that struggling population swims into Cape Cod Bay. Mothers come into these sheltered waters with their young calves to nurse, adults gather in “social groups,” and if all is right with the world, everyone feeds on thick swarms of zooplankton, patches of tiny copepod crustaceans so dense they turn those cold dark waters bright orange. And when the whales were in the bay, we would head out there every day we could to meet them—to photograph and identify individuals and observe their behavior. My particular job was to try to learn more about what exactly they were eating and help gather any clues about how they found that food.

It was cold out there. Really cold. Often our cruises would start before first light, and we wouldn’t get back to our harbor mooring until well after sunset. We worked off an old lobster boat, the Halos, that was smaller than most of the whales we were studying. Some mornings we had to scrape the ice off the decks. For this job, understanding the perfect combination of work gear was an essential skill to acquire. Knowing just the right recipe made all the difference: layers of thermal underwear, and sweatpants, two or three pairs of socks (maybe with a little cayenne pepper sprinkled in between the layers for extra heat), thick woolen fingerless gloves over lightweight nylon liners, mufflers and sweaters and balaclavas, and over everything, great big fluorescent water-resistant thermal overalls that looked just like a little kid’s bulky snowsuit. When you were finally fully dressed and ready for work, the only part of you showing would be your eyes and the bridge of your nose.

Except for the whales and us, it was completely deserted out there that time of year. On calm days when we weren’t having any luck sighting whales, we would cut the engine and drift for a while. We would silently wait, just listening. Eventually, we might hear the low whoosh as a whale exhaled after coming up from a long dive. There were times when we could hear the blows all around us, without ever seeing a single animal. We would pick out the sound of one powerful deep breath among many, and head off in that direction. Miles away, we would find them.

Being out there with the whales that time of year was an absolutely wonderful, absolutely beautiful, absolutely brutal experience. As far as I’m concerned, it was the best job in the world.

Andrew is a science journalist and author who has written several books for Sally Ride Science including Our Changing Climate: The Atmosphere.

If the economy goes bad, could that be good for the environment?

That provocative idea lurks in the shadows of a recently published study that found the rate at which we’re pumping carbon dioxide into the atmosphere is increasing rapidly.

Why the big growth? For the most part, it’s because the world’s economy is on a roll. And when times are good, we do more of just about everything, like build houses, shop at the mall, and zip around by car or jet. All those things require energy and—more frequently than not—put more CO2 into the atmosphere.

The amount of the greenhouse gas released into the atmosphere increased just 1.3 percent a year during the 1990s; between 2000 and 2006, as the world economy boomed, emissions grew by 3.3 percent annually, scientists estimate. The scientists pin about two-thirds of the increase on industrial growth, according to a study that appeared in October in the Proceedings of the National Academy of Sciences.

But that’s not the whole story: what’s called the “carbon intensity” of the world’s economy also is on the rise after several decades of decline. What’s that mean? Simply put, the amount of carbon dioxide—whether from burning coal, oil, or gas—that’s emitted in making everyday things is growing. (More accurately, carbon intensity is measured by the amount of carbon emitted per dollar of economic activity.)

For example, compare a widget factory run on electricity generated by the wind compared to one that runs on juice supplied by a power plant that burns coal. Widgets made at the first factory rely on a clean energy source and thus are less “carbon intense” than those made at the second. In the real world, the building of coal-fired power plants—and the factories they power—in places like China, fast becoming a major manufacturer of just about everything, is partly to blame for the stepped-up carbon intensity of the global economy.

That’s still not all, though. The scientists also found the Earth’s land and oceans are becoming less efficient at sopping up the carbon dioxide we produce. Currently, they can absorb about half our CO2 emissions; scientists fear that proportion will shrink. Previously, some hoped that an atmosphere richer in CO2 would stimulate plant growth and help keep levels of the greenhouse gas in check. That may not be the case.

So what to do? No one is out there rooting for factories to close, workers to lose their jobs, or retail sales to plummet. But what if that did happen? Well, CO2 emissions in many of the formerly communist countries in Eastern Europe plummeted after their economies collapsed in the years immediately following 1989. There’s no reason to believe that wouldn’t be the case if the economy went south on a global scale, too.

There are other less devastating and disruptive ways to get there, too. One is to encourage developing countries to drop coal for less carbon-intense energy sources, like natural gas, nuclear, wind, or solar power. Another is to encourage greater efficiencies in how energy is used, whether to make electricity, run factories, or move people around. All would help reduce CO2 emissions, the largest contributor to the effect our activities have on climate change.

Laurie is a science and environmental journalist and author. She wrote the Sally Ride Science book Our Changing Climate: The Oceans.

Over the next months and years, our world leaders will be considering proposals and grinding out an international response to climate change. As I was reading up on that and the Bali conference, one number jumped out at me right away: 2050.

That’s the year proposed by the European Union as a target for reducing global greenhouse gas emissions to 50 percent of 1990 levels. It’s generally regarded as an ambitious commitment. Given where we stand now, I’m sure it is.

Mention of that year just popped out at me when I read today’s news. Because in my research for the Sally Ride Science book I wrote, 2050 came up all the time. It’s all over the place, as scientists anticipate where the current trends they are seeing in their respective fields will lead us by midcentury.

Comparing this “bold” target with scientists’ most informed predictions and extrapolations just illustrates how the timelines between science and politics are seriously out of whack. The debate has begun as to whether 2050 is just too darn early to pin governments down to such severe greenhouse gas emission restrictions. So, this seems like a good time to gather up just a few examples of what various scientists have said about how the world will look in 2050 if global warming and rising CO2 levels continue on their current trajectory.

• By 2050, if ocean temperatures have increased by just 1.5°C, 95 percent of the corals on Australia’s Great Barrier Reef will be lost.
• The Arctic Ocean could be completely ice free during the summer, by 2050. Unless, of course, it happens earlier...
• By 2050, ocean surface waters will be so acidic from CO2 that it will be impossible for corals and many other important marine species to grow their calcium carbonate shells or exoskeletons. Entire food webs that depend on many of these organisms could collapse.
• Due to climate change related causes, possibly as much as one fourth of the world’s plant and invertebrate species may be extinct by 2050.
• By 2050, as many as 150 million of the world’s inhabitants could be “environmental refugees”, driven from their homes by rising sea levels or drought, the result of global warming.

These dire predictions notwithstanding, I have to confess that the year 2050 often seems pretty abstract and almost comfortably distant to me--until I consider exactly what it means in the arc of my own family’s life.

Obviously, by 2050, if I’m around at all, I’ll be wicked old—I don’t even want to think about just how decrepit I’ll be. But my daughter and son: well, they’ll be just a little bit older than I am now. And as a mother, I know that particular passage of time is going to seem like no more than the blink of an eye.

It’s self-centered and quite unscientific, but that helps put this all into context for me: these big ideas and unwieldy debates are relating to mighty nasty things that will be happening right smack in the middle of our children and students’ lives—if not sooner…

Laurie is a science and environmental journalist and author. She wrote the Sally Ride Science book Our Changing Climate: The Oceans .

The United Nations Conference on Climate Change opened this morning in Bali, Indonesia. There have been quite a few important UN meetings this year on climate change—most of the others we’ve read about in the news during 2007 were basically scientific gatherings of the UN Intergovernmental Panel on Climate Change (IPCC), where researchers from around the world gathered to present their observations of global climate change, and based on those findings, make their best predictions for what the future holds. Last month they completed that task and handed over their final report: a devastating appraisal of the likely environmental, economic and social costs of current global warming trends. But this meeting in Bali is different from those IPCC conferences: now it’s time for the movers and shakers--government representatives from 180 nations around the world--to return to center stage. The scientists have arguably given the topic their best shot, and now it’s a matter of what the rest of us will do with this information. Can’t say we haven’t been warned…

In comparison to the challenge just met by those IPCC scientists, who had to sort out the complexities of literally a planet’s worth of scientific data into one comprehensive document, the main goal of this two-week meeting seems pretty simple: just hammer out some sort of preliminary timeline, or roadmap, for how negotiations on the next set of international agreements for fighting climate change will proceed. The Kyoto Protocols expire in 2012: where will we go from there? This meeting is just to start the wheels rolling—it’s like the very first get together of a global party planning committee. And yet the sad fact is that given the overwhelming number competing national interests, and especially the resistance of the United States government to engage in any meaningful international discussion, even this relatively humble objective will be an enormously difficult task, and few are optimistic about how much will actually be accomplished by the time the conference closes.

Associate Professor of Integrative Biology
University of Texas at Austin

Camille was a featured scientist in the Sally Ride Science publication Our Changing Climate: Ecosystems . For our blog, she would like to share her article that was published in Gincana 3, a publication of the Secretariat of the Convention on Biological Diversity, United Nations (2007).

Will global warming lead to the sixth mass extinction event? Or will life be more resilient? Will the teeming biodiversity that we now enjoy collapse down to a few, extremely hardy souls, or will evolution save the day? Climate change is a natural part of Earth's history, so why worry? Answers are even now upon us—both extinctions and adaptations are already happening, and both will continue to shape life as we know it over the coming centuries and millenia.

The study of impacts of climate change is not a new topic in biology. It has a rich history in the scientific literature, since long before there were political ramifications. Way back in 1917, a scientist named Grinnell concluded that the geographic boundaries of many species were determined by climate—individuals living at the edge of their range were living in as extreme an environment as the species could tolerate and survive. The history of biological research is full of studies of the impacts of weather and climate change on wild species. During the 1930s and 1940s, the climate in northern Europe “ameliorated,” bringing warm summers and mild winters. Researchers published a plethora of papers about earlier spring flowers and northward expansions of the ranges of birds and butterflies. In the 1960s and 1970s, European climatic conditions became “harsh”, with cold and wet summers starting about 1950. A second wave of papers came out documenting the lateness of spring flowers and the southward contractions of the same species of birds and butterflies that had earlier expanded northwards. Given the dynamic nature of Nature, it’s no wonder that the public is confused about whether or not to worry about global warming.

Why is human-driven warming any different from recent natural variation in climate, such as that experienced in northern Europe over the 20th century? The answer is simple. Natural warming and cooling trends have been like a lone car on a deserted highway not bothering to stay in lane: the wobbles back and forth have been relatively small, short term, and there's a strong tendency to move back to the middle. Global mean temperature has hardly changed in the past 10,000 years. But now we are changing from an earth with temperatures that fluctuate a bit to one that will be warming into the foreseeable future. Whether you imagine this as the car heading off onto a new, unexplored highway, or just going into the ditch—a major climatic shift is in progress. If we want to predict the impacts of human-caused change in global climate, our best clues can be found by looking, not at biological impacts of twentieth-century fluctuations but much further back in time to when climate truly did show shifts of the magnitude that we now anticipate.

If we look over the past few hundred thousand years, we see in the fossil records that the freezing and warming cycles of the Pleistocene glaciations caused massive relocation of plants and animals. Range shifts of thousands of kilometers were common as Earth went from a glacial age (when much of Europe and North America were covered in ice) to an interglacial age (as we’re in now). If we go even further back, to when Earth was much warmer than today (several million years ago), we see that many species did go extinct in the transition from this “hot” Earth to the Pleistocene “cool” Earth. Most species that were adapted to "hot" Earth are long gone. Species that survived are adapted to a relatively cool Earth. Human-driven global warming is taking us into a future which is warmer than it has been for thousands, and possibly for millions, of years—to an Earth that will lie outside the evolutionary experience of many plants and animals currently living. It will be no surprise if these species suffer high extinction rates.

Less than 10 years ago, as this information was sinking in, biologists were struggling to foresee the future. Which species would be most sensitive to global warming? How many species would go extinct? Would there be winners as well as losers? I was involved in several independent teams struggling with these questions—from conservation organizations like the IUCN to scientific panels like the IPCC—and the conclusions were remarkably similar. While no-one felt that predictions about particular species could be made, the consensus was that the species most affected by global warming would be those restricted to cold climate habitats, like Earth’s poles or mountain tops, and those able to tolerate only a narrow range of temperatures (e.g. tropical corals). Less than a decade later, those very predictions have been borne out.

Mountain species are following the climates to which they are adapted by shifting their ranges to higher elevations. However, for a population already at the top of its mountain, the preferred elevation now contains only sky. In many regions, high-elevation species are being pushed off their mountaintops. We see this in the American pika—an adorable little mammal well known to mountain back-packers for skittering along talus slopes carrying flowers in its mouth. We see it again in an icon for European naturalists—the Apollo butterfly­—whose translucent white wings with their bright red patches glide effortlessly between craggy mountains. The Apollo butterfly and the pika have lost many of their lowest populations and are gradually becoming confined to only the highest mountains.

What of the ultimate "cold-Earth" species—those whose habitat is actually floating sea ice? Surprisingly, none have gone completely extinct; but as sea ice declines, populations are declining in numbers, and their ranges are slowly contracting poleward. The Emperor and Adélie penguins have declined by 70% - 95% at their most equatorial populations in Antarctica (along the Palmer Penninsula) as sea ice has steadily shrunk or disappeared. But more worrying for their long-term future is that even some populations closest to the South Pole have declined. The Arctic has its own martyrs. There's an emerging debate as to whether the polar bear should be the first species to have its official cause of decline listed as “global warming” under the U.S. Endangered Species Act.

At the other end of spectrum, systems that we associate with hot beaches, bath-warm waters and cold drinks—species that we might think would be hot-adapted—are also suffering. Sixteen percent of tropical coral reefs worldwide were killed off by heat during the single extreme El Niño of 1997/1998. A coming threat is the increasing acidity of the oceans. The pH of tropical waters has already dropped from 8.2 to 8.1 as carbon dioxide is absorbed and converted to carbonic acid. As pH continues to drop, the ability of animals to construct hard shells will decline dramatically. Some coral biologists fear that “business as usual” projections could lead to tropical corals being unable to build and maintain reefs by 2050.

We're seeing impacts of current warming on every continent and in every ocean. We're also seeing very similar responses in very different types of organisms—from butterflies in Finland to fish in the North Sea, from foxes in Canada to trees in Sweden, from birds in Antarctica to starfish in Monterey Bay, California. Forty-percent of wild species are showing changes in their distributions - shifting their ranges north and south towards the poles and up mountains. An astonishing 62% are showing changes in their seasonal timing—spring is earlier and fall is later. Birds arriving for their spring migration, butterflies emerging from overwintering, trees leafing out after winter dormancy and the first blooms of flowers are all about two weeks earlier than they were 30 years ago across the northern hemisphere. My colleague, economist Gary Yohe, recognized that this was what economists would call a “globally coherent” signal of climate change impacts in natural systems across the world. This coherence—this systematic pattern—is important because it tells us that species and systems for which we don’t have any data are likely to be showing similar responses to those with detailed, long-term data. Globally, we estimated that half of all wild plants and animals have been affected by recent, human-driven climate change.

While geographic patterns of humans contracting different diseases is well-documented, the distributions in the wild of organisms that cause those diseases are often not well-studied. However, parasites that cause tropical diseases are not fundamentally different from other wild species. We therefore expect them to respond in the same way as more charismatic species for which we have better long-term data on their natural distributions. Just as tropical birds and butterflies have spread into Europe and the USA, we expect, then, that parasites and their vectors will extend their ranges from the tropics towards the poles, introducing human diseases as they invade new areas. In fact, human health is already being affected. For the year 2000, the WHO estimated that 6% of malaria infections, 7% of dengue fever cases and 2.4% of diarrhea could be attributed to climate change. This is principally due to increased frequency and intensity of flood events, which in turn have been linked to human-driven global warming. These numbers are likely to grow as these diseases expand their geographic ranges.

We can already see more severe effects of disease spread in the wild world, particularly for a group of amphibians appropriately named "harlequin " frogs. These bespeckled jewels of the clouds have served as poster-children for preservation of tropical cloud forests. Ironically, now that many sites have successfully been protected, global warming has crept from behind and staked its claim. Seventy-four species of cloud forest harlequin frogs have gone extinct in Central America. They aren't dying because they're too hot, but because climatic conditions have now become perfect for a deadly fungus. As this fungus invades the mountains, even some of the highest elevation species have been lost.

Some species, those with short generation times like insects, are showing genetic adaptation—evolution—in response to climate change. Unfortunately, these changes are small and unlikely to protect species from climate-caused extinction. Even though the frequencies of existing "hot-adapted" genotypes are increasing across populations in many species, truly new traits are not emerging. We are not seeing new mutations that would allow species to exist in climates outside their previous range of tolerance. In other words, species can play around with the genetic variation they already have, but evolving new, even “hotter” adapted genotypes, is a process that’s likely to be too slow to keep pace with rapid, human-driven climate change.

The good news is some northern-hemisphere species are able to move their ranges faster than we thought they could as climate warms at their northern range boundaries. These are species that already had a few individuals that were good at moving. The proportion of “movers” has increased at the range boundaries, and this local evolution has allowed these species to expand northward into new territories very rapidly. More good news is that some species that are adapted to a wide array of environments—globally common, or what we call weedy or urban species—will be most likely to persist.

So what will life on Earth look like over the lives of people now being born? There’s obviously a range of possibilities, depending on how policy-makers and the public as individuals decide to change our habits. What are the possible future worlds? Even the minimum projections - of another 1.8° C - are more than twice what we’ve already seen. All of the changes I talk about above have occurred with just 0.7° C warming. “Business as usual” projections are for another 4° C rise, with some models estimating over 6° C rise in global temperature. These higher projections represent a climate the Earth hasn't had long-term exposure to for several million years - outside the evolutionary history of much of life on earth now. Temperature changes of the that magnitude (> 6° C) in the past have often led to substantial extinction events, especially if the climate change was rapid. We need to implement major emission reductions now so that we keep future global warming down to those lower projections—down to “just” another 1.8° C. We can’t afford the worst case scenario either in terms of conservation of biodiversity, human health, or our economic stability.

Reprinted by permission of Secretariat of the Convention on Biological Diversity.

Wildlife Biologist, Polar Bears
U.S. Fish and Wildlife Service
Anchorage, Alaska

In recent months much public attention has been given to potential effects of climate change on the world-wide population of polar bears. In January 2007, the U.S. Fish and Wildlife Service (FWS), responsible for polar bear management in the United States, proposed to list the species as “Threatened” under the Endangered Species Act, due to effects of climate change on sea ice. We received over 600,000 public comments, indicative of high public concern regarding polar bears and the Arctic habitat in which they live. In September 2007, the U.S. Geological Survey’s AlaskaScience Center released 9 reports regarding the relationship of sea ice changes and polar bears, including a quantitative assessment of population status projected into the future. Climate change issues are playing an increasingly prominent role in both research and management activities.

One interesting aspect of polar bear life history that we have been monitoring since 2000 is the use of terrestrial habitat along Alaska’s Beaufort Sea coast (between Barrow and the Canadian border) by polar bears. Polar bears in this region historically have spent the majority of their lives at sea, using marine ice as a platform for hunting/feeding, resting, traveling, breeding, and to some extent, for maternal denning. In recent years, however, increasing use of terrestrial habitat has been reported, especially during fall months. This raised concerns because of the potential increase in bear-human conflicts in both coastal villages and oil and gas development areas. The FWS has been monitoring coastal use by polar bears through two studies: 1) aerial surveys to document the distribution and abundance of polar bears using the Beaufort Sea coast prior to winter freeze up; and 2) ground-based observations of polar bears feeding on bowhead whale carcass remains left from Alaska Native subsistence whaling activities. To date, these studies have provided a few interesting findings:

1. In 2000-2005, the number of bears on land increased when sea ice was furthest from shore, indicating that the position of pack ice edge is a primary factor in determining how many bears occur along the coast;
2. The distribution of bears on shore appears to be related to a combination of ringed seal density near shore, as well as to the availability of marine mammal carcasses;
3. Polar bears feeding on marine mammal carcasses were frequently observed feeding side by side in close proximity of each other with minimal conflict among age/sex classes of bears;
4. Brown bears also used marine mammal carcasses and, although much smaller in size than polar bears, tended to be socially dominant and displace polar bears from the feeding site.

At present, the proportion of southern Beaufort Sea polar bears using terrestrial habitat during the fall open water period is pretty low (<10%); however, long term reduction of sea ice could result in an increasing proportion of bears using coastal habitat for a longer period of time. While marine mammal carcasses can provide an alternative food source when bears are waiting for freeze-up, their proximity to human settlements may also result in an increase in problem bear-human interactions and potentially, in increased polar bear mortality. The FWS continues to work with both village residents as well as oil and gas operators to minimize conflicts, e.g. by assisting with polar bear deterrence programs and by providing guidance on reducing bear attractants. Information from these studies is also used for environmental assessment for oil and gas lease sales, exploration and development projects, and oil spill contingency planning. Results from the studies mentioned above are currently being prepared for publication.

Our world is getting warmer and our oceans, the largest of ecosystems, are feeling the heat. Oceans keep our planet healthy. They cover over 70 percent of the globe and are home to 80 percent of all life on our planet from seaweed to sharks.

During the last century, Earth’s air temperature has risen almost a full degree Celsius which means that the world is warmer now than at any time in the last 1000 years! The three warmest years on record have all occurred within the last ten years; 19 of the warmest 20 since 1980.

The oceans are warmer too. Worldwide, the average temperature of the oceans has risen almost one-half a degree Celsius in just the last fifty years. Doesn’t sound like much? Well it is!

Remember, the half a degree Celsius is averaged all over the globe. In tropical waters, average temperatures have risen as much as 1.7 degrees Celsius and many coral reefs are struggling to survive. When ocean temperatures get too high, corals lose the colorful algae that live inside them and turn white or bleach. Twenty-five percent of the world’s coral reefs have already been destroyed.

Arctic waters are even warmer and sea ice is melting faster than ever before. Since record keeping began in 1978, summer sea ice has been shrinking by about 60 million square kilometers (23 million square miles) each year. That’s like losing half of Ohio every summer. Experts predict the Arctic summertime ocean will be completely ice free well before the end of this century.

What happens when sea ice starts disappearing? Animals that depend on it to hunt go hungry. Canada’s Hudson Bay is now ice-free three weeks longer than it was thirty years ago. Hence, the polar bear population there has dropped 22 percent.

In the Antarctic, the number of Emperor penguins has shrunk by 50 percent during the past 25 years. Why? There is less sea ice to support the tiny shrimp-like krill that these penguins feed on.

And of course, the oceans are rising with the expanding warmer water and melting glaciers. Between 1993 and 2003, sea levels rose at an average rate of 3 mm (0.1 inch) per year. In this century the ocean will swell anywhere from 18 to 59 centimeters (7 to 23 inches). Still want that beach front home?

The changes we see in our oceans are just beginning. If we don’t control global warming, the oceans will continue to warm, sea levels will continue to rise and sea life as we know it, will cease to exist. The oceans are too precious of a resource not to try and save them.