Archive for the 'climate change and history' Category

Published by Rosalind on 20 Nov 2010

Scientists study ice for clues to future

Is it possible that global climate change could cause sea levels to rise as much as six feet? Researchers are studying glacial ice and hoping to find the answer to the question. Even much smaller sea level rises would be a huge problem for people worldwide, as cities built by the ocean or by rivers would see flooding and damage to infrastructure like ports. Some low-lying coastal communities would be obliterated unless they could find ways to protect themselves from the rising waters.

Scientists all over the world are trying to find ways to predict the effects of climate change and specifically the rising average earth temperature. Glacial ice is being affected by rising sea temperatures in places like Greenland, where sea water temperatures of 40 degrees can melt the ice from beneath while air temperatures impact it from above.  You can read about some of this work here: Reading Earth’s Future in Glacial Ice.

Published by Rosalind on 06 Sep 2009

Changes in the Arctic

Are we living in the Anthropocene age? That would be the time when humanity’s influence becomes the main geological influence on the earth. In this post, Andy Revkin of the New York Times, talks about a new study which seems to show how deeply human influences on the climate – including greenhouse gas emissions and air pollutants – are affecting the Arctic. Check it out here: Humans may have ended long Arctic chill .

Published by Diana on 31 Jan 2009

How we know what we know about carbon dioxide and climate

In the 1950s, a scientist named Charles Keeling started doing the kind of scientific work that looks boring but leads to incredibly important discoveries. It can take hundreds or thousands of observations–collecting information–before a scientist sees a pattern. Imagine, for example, how long it would take to realize that the sun follows the same path through our heavens every year and that it is predictable. Humans built Stonehenge to track solar observations–just one example of how important information gathering can be.

Charles Keeling began to measure the amount of carbon dioxide in the air, in just one place, regularly. Sometimes he took measurements several times a day. He made his measurements at the top of the dormant Hawaiian volcano Mauna Loa, where he could be sure he wasn’t measuring carbon dioxide produced by local sources like a power plant or a fireplace. He wanted to be sure he was measuring the carbon dioxide normally found in the air.

He found the level of carbon dioxide in the air increased a bit in the spring, and fell in the fall, as the planet went through its seasons. You can see the curve in this Wikipedia article: Keeling Curve. He also found that the level of carbon dioxide in our air was increasing steadily.

But it took YEARS of observations–made often–before scientists could be sure of what they were seeing. Keeling must have thought “do I have to make this observation?” at least a few times. Yet he kept on, and he made observations regularly from 1958 to 2005. His son continues to make observations regularly now.

National Public Radio did a great broadcast about Keeling recently: check it out here: NPR on Charles Keeling.

Published by Diana on 28 Jan 2009

More information on Antarctica

Scientific American has produced a very nice podcast on the Antarctica warming information: podcast.

In doing a lot of reading about this report, I’ve found a few things especially interesting. There’s an ozone hole over much of Antarctica, and where there’s the ozone hole, it’s cooler. But even with the ozone hole, and Antarctica’s fierce winds, average temperatures are up a full degree (and scientists always talk in Celsius degrees, so almost two degrees Farhrenheit) since 1957, when they started keeping records of temperatures there.

Published by Diana on 21 Nov 2008

More Science Needed

Sometimes I read an occasional article saying that science has solved all the big questions, and then I read an article like this one: Invasive Plants in Galapagos May Really Be Native.

Science isn’t really that easy. The Galapagos have been studied in detail since Charles Darwin did his studies on finches there in the 1830s (on one of the first global scientific studies). The islands aren’t that big. And it’s only now that scientists are doing the pollen studies on what plants have been there over history. And those pollen studies are showing that they need to do more research.

What does this have to do with climate change? Well, one key part of studying the current changes in our climate is studying past climates. One way to do that is to look at what plants were found where in the past. For example, tropical trees like palms generally indicate a warmer local climate. So scientists need an accurate picture of what plants lived in what parts of the globe THEN and NOW so they can study climate change.

Published by Rosalind on 12 Nov 2008

Did Fall Come Later This Year?

                                                     Fall Color 2008 — Adirondack Mountains

Every year everyone in the Northeast United States tries to forecast when the amazing fall leaves will reach their peak color. The newspapers publish maps showing the color changes, and the tourists and local folks drive through the woods enjoying the show. In 2008, in the Catskill and Adirondack Mountains of New York, local observers agreed that fall leaf colors continued to peak later than they did in the past. Twenty years ago, the Columbus Day Weekend — around October 12th — was considered the average peak color in the Catskills. In the last few years, fall leaf color has peaked towards the end of October.

Local scientists have documented changes in the local climate that seem to provide clues to that change. Climate monitoring at the Mohonk Lake Cooperative Weather Station (reported by the Mohonk Preserve’s Daniel Smiley Research Center) shows that the average temperature has risen 2.7 degrees Fahrenheit over the last 112 years. The local growing season is now an average of ten days longer, too. If these changes continue, peak leaf color in the Catskill Mountains may become a November event — and the types of trees in our forests may also be affected by the new growing conditions.

Published by Rosalind on 09 Nov 2008

The Ozone Hole

NASA Ozone Hole September 2008
NASA Image of Ozone Hole, September 2008


In September, when cold temperatures and sunlight begin to appear over the Antarctic horizon and start to drive chemical reactions that destroy ozone, the yearly hole in earth’s ozone layer is at its biggest. An important chemical in these reactions is chlorine, which comes from manmade chlorofluorocarbons (CFCs). By October, the ozone-destroying chemical reactions stop. From October to December, the ozone depleted region moves south, so there’s less atmospheric ozone over parts of the USA. NASA’s satellite data shows that this year the ozone hole grew to its largest size on Sept. 13, reaching a maximum area extent of 9.7 million square miles. That’s larger than the area of North America.
NASA scientists say that this size is fairly similar to the sizes observed over the last decade. But it is still huge, particularly when you consider that the ozone hole didn’t exist at all until the 1970’s. Some scientists think that the ozone hole will slowly shrink now that CFC’s are banned by an international treaty. The ozone hole doesn’t appear to be a cause of climate change — instead the hole is caused by some of the same atmospheric gases that cause global climate change. If the hole is closed, some scientists think it will help reduce the warming of Antarctica, so it’s all connected! You can read about the study here:  Mending Ozone Hole

Published by Diana on 05 Nov 2008

Our New President-Elect and the State of the Environment

Within minutes of Senator Barack Obama’s becoming our new President-elect, articles began to appear to suggest what legislation he should propose to deal with the pressing problems facing the United States. The Union of Concerned Scientists makes a great case that those problems can be addressed with a unified approach: “We are looking to the new president and Congress to work together to build a clean energy economy that will create millions of new jobs here at home, expand capital investment, make our nation less dependent on oil, and prevent the worst consequences of global warming.” Taken from this article: Obama Administration, New Congress Should Mean Aggressive Approach to Global Warming, Science Group Says.

Published by Diana on 21 Oct 2008

Natural Air Pollution

We all tend to think of air pollution as something only humans cause. But one big source of air pollution is volcanoes. On the Big Island of Hawaii–the biggest of the five major islands that form the state of Hawaii–there are five volcanoes, and one of them is actively producing a lot of sulfur dioxide right now.

Sulfur dioxide combines with the water in the air to form a volcanic fog–called vog by some people–that tastes a bit unpleasant and which causes a haze in the air. Longterm, it can cause damage to people’s lungs, and to plants and animals. You can see the vog over the town of Kailua-Kona in this picture:

The view toward Kona through the vog

The view toward Kona through the vog: photo by Jay Torborg

Volcanoes are well known to cause global climate change. In the years following the eruption of Tambora in Indonesia, which took place in 1815, global climates were much cooler than average, partially because the dust from the volcano reduced the amount of sunlight reaching the earth’s surface.

More information about Hawaii’s volcanoes can be found at the United States Geological Survey website: Hawaii Volcanoes Observatory.

Published by Rosalind on 17 Oct 2008

More than 25% of the world’s mammals are at risk

A family of elephants in Tanzania's Serengeti National Park--photo by Jay Torborg

A family of elephants in Tanzania: photo by Jay Torborg

On October 10, the IUCN (International Union for the Conservation of Nature) released a shocking report. This year’s update of the Red List of Endangered Species shows that more than a quarter of the world’s mammal species are at risk of extinction.

The IUCN Red List report summary says: “The new study to assess the world’s mammals shows at least 1,141 of the 5,487 mammals on Earth are known to be threatened with extinction. At least 76 mammals have become extinct since 1500. But the results also show conservation can bring species back from the brink of extinction, with five percent of currently threatened mammals showing signs of recovery in the wild.”

To read more about the report, go to Red List

These two photos from our Serengeti trip are by Jay Torborg, a wildlife and underwater photographer who lives in Sammamish, Washington–and who is married to Diana.

Serengeti cheetah surveys the tall grassland--photo by Jay Torborg

Serengeti cheetah surveys the tall grassland: photo by Jay Torborg

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