October 30, 2009, 17:00 PDT

A world of extremes

When it rains, it pours

Climate change and weather
Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.

We can expect more weird and wacky weather in the future, and it’s thanks to climate change, say scientists.

According to Dr. Gerald Meehl, a senior scientist at the National Center for Atmospheric Research (NCAR), as the planet warms up, even if it’s by a relatively small amount, the result will be more extreme weather. “By itself, global warming doesn’t cause extreme conditions, but it makes naturally-occurring events even more extreme,” explained Meehl during a visit to NASA’s Jet Propulsion Laboratory earlier this month.

And it’s those extremes — not the averages — that cause the most damage to humans, wildlife and ecosystems. By combining real-world observations with climate models, researchers at NCAR have come up with projections for future changes in weather extremes. Climate models, which are akin to weather forecasts, predict future climate change by taking into account the atmosphere, oceans, land, sea ice and the complicated interactions between them. They also include the effects of changes in greenhouse gas levels, the heat output of the sun and volcanic explosions here on Earth. Today’s climate models can resolve climate and weather effects down to a scale of 35 km (22 miles) — enough to be able to identify category 3 hurricanes.

Meehl, who has been active in writing the Intergovernmental Panel on Climate Change (IPCC) climate change assessment reports, says that we can look forward to:

  • More frequent and longer-lasting heatwaves. In the U.S., for example, there will be many more heatwaves in the Pacific northwest where at present there are few.
  • More moisture from individual precipitation events (rainfall, snowfall, etc.), but longer dry spells in between those events. Ultimately, soils will get drier in the southwest U.S., where there will be more droughts, and wetter in the northwest.
  • Interestingly, there will be fewer hurricanes and tropical cyclones, but the ones that form will be much more intense. As oceans warm up, they provide more energy that fuels storms and makes them more violent. But the number of storms is likely to drop as a result of changes in the vertical wind structure of the atmosphere.
  • More record hot temperatures and less record cold temperatures. Right now, the ratio of the number of record high to record low temperatures is about 2:1. But a new paper from Meehl et al. published in Geophysical Research Letters ("Relative increase of record high maximum temperatures compared to record low minimum temperatures in the U.S.") says that ratio will become 20:1 by mid-century, and 50:1 by the end of the century. Note that even in a warming climate, we still get cold snaps — Meehl says it’s the relative proportions of cold and hot snaps that change. (Read this and this to learn more about why it is possible, and natural, to have cold spells in a warming world.)

(For more on the difference between weather and climate, take a look here.)

October 27, 2009, 17:00 PDT

Pick of the pics

Byrd Glacier, Antarctica

Byrd Glacier, Antarctica

Named after the American polar explorer Richard Evelyn Byrd, the Byrd Glacier is a major glacier in Antarctica, about 15 miles (24 km) wide and 100 miles (160 km) long. It is known as an outlet glacier because it is a "tongue" of the main ice sheet and extends into the ocean. It plunges through a deep valley in the Transantarctic Mountains and drops more than 4300 ft (1300 m) over a distance of 112 miles (180 km) as it flows into the Ross Ice Shelf. The fast-moving stream is one of the largest contributors to the shelf's total ice volume.

This image was taken in January 2000 by Landsat 7, an Earth-observing satellite that was launched into orbit in 1999.

October 18, 2009, 17:00 PDT

Adapting to climate change

Governors put their heads together

An assortment of luminaries attended the Governors’ Global Climate Summit earlier this month, ranging from Arnold Schwarzenegger to Tony Blair to Harrison Ford. NASA Jet Propulsion Laboratory’s very own Kevin Hussey (pictured) was there to preview our interactive tool.
An assortment of luminaries attended the Governors’ Global Climate Summit earlier this month, ranging from Arnold Schwarzenegger to Tony Blair to Harrison Ford. NASA Jet Propulsion Laboratory’s very own Kevin Hussey (pictured) was there to preview our Eyes on the Earth interactive tool.

“When we come together and work as a team, we can achieve the seemingly impossible.” So began the Governors’ Global Climate Summit (GGCS), held in Los Angeles at the beginning of this month, on a hopeful note.

Billed as a stepping stone to the U.N. climate treaty talks in Copenhagen this December, the GGCS brought a variety of movers and shakers together: governors from regions and states all over the world, U.N. officials, former British Prime Minister Tony Blair and Jane Goodall (the world’s foremost authority on chimpanzees and an avid conservationist), to name but a few. It was the second time California Gov. Arnold Schwarzenegger had co-hosted the event, having promised to return last year with his signature line “I’ll be back”.

As Gary Gero, president of Climate Action Reserve, said at the meeting, “Subnational governments are the ones that are going to be ultimately responsible for implementing much of what gets negotiated at the discussions in Copenhagen. We have to make sure that their voice is heard.” Lisa Jackson, administrator of the U.S. Environmental Protection Agency (EPA), agreed: “For too many years, states, cities and towns concerned about climate change have had to go it alone — typically without federal partnership, and sometimes with aggressive federal opposition.” That’s why she announced in her speech on the opening day of the summit that the EPA would be moving forward on its own with a new proposal to reduce greenhouse gas (GHG) emissions, with or without stronger climate legislation from Congress and the Senate. It plans to use the Clean Air Act to regulate the emissions of facilities that produce more than 25,000 tons of carbon dioxide per year and to ensure that they adopt the most efficient technologies when they are built or upgraded.

While mitigating (trying to minimize) climate change is crucial, Dr. Stephen Schneider of Stanford University explained that for most countries it will be a case of adaptation, not mitigation. “The primary victims [of climate change] are those who did the least to cause the damage.” Water issues were top of the agenda. Rick Miles, minister of the environment of New Brunswick, Canada, put it this way: “Climate mitigation is all about energy. Climate adaptation is all about water.” Sea level rise is a major concern for both small island states such as the Maldives and larger countries. As Ann Veneman, executive director of the United Nations Children’s Fund (UNICEF) and former U.S. Department of Agriculture secretary, explained, China, India and Bangladesh represent 75 percent of all flood mortality risk. Meanwhile Dr. Dessima Williams, chair of the Alliance of Small Island States said, “We are under threat. An emergency is emerging around the small island states. 2 ℃ warming is not enough. We need to limit it to 1.5 ℃.” (The Maldives just held a rather unorthodox underwater cabinet meeting to press home the point.)

Other regions such as the Horn of Africa are at risk of severe drought and crop failure. According to Veneman, women and girls will likely be impacted more by climate change than men. They make up 70 percent of farmers and will suffer when crops fail; moreover, they are the ones that fetch water and will have to walk further to find it.

For many countries, the inherent uncertainties that surround future climate change predictions are making adaptation decisions difficult. Many are therefore trying to prepare themselves for the worst-case scenarios if they can afford it. But it won’t come cheap. A new study from the World Bank suggests that it will cost $75-100 billion each year to adapt to climate change from 2010 to 2050. Who is going to pick up the tab?

The upcoming Copenhagen negotiations are seen by many as a once-in-a-lifetime opportunity, the last chance to act. Whether the sense of urgency shared at the governors’ summit will translate to the global stage remains to be seen.

October 14, 2009, 17:00 PDT

Round up, round up

Blog Action Day

The blogosphere.

Today is Blog Action Day, which aims to bring about the "largest-ever social change event on the web". Over 10,000 bloggers in 150 countries are joining together to write about climate change today. Since we write about climate change all the time here on my big fat planet, I thought we’d take a look at some highlights from elsewhere in the blogosphere so far…

  • Nettuts+ wrote about the top 20 ways web developers can reduce their carbon footprint. While the topic might not sound thrilling, here are a few interesting tidbits:
    • Use an eco-friendly font. Yes, an eco-friendly font actually exists. It saves on average 20 percent more ink than other fonts, by craftily removing parts of the letter you would never notice anyway.
    • Don’t use a screensaver. They still use power, and actually keep your computer from going into full power-save mode.
    • Add a plant or two to your office (they give out oxygen and absorb carbon dioxide). A New Delhi company found that by adding three different types of plants to their offices they reduced eye irritation, headaches, lung issues, and respiratory system incidents over the course of 15 years. They also cut their energy bill by 15 percent.
  • The Tcktcktck campaign has released a new video in honor of Blog Action Day, urging world leaders to make the right promises at “the most important meeting in the history of the world”. They’re referring of course to this December’s U.N climate treaty talks in Copenhagen, and the video is part of their efforts to help make a “fair, ambitious and binding” deal happen.
  • Google gave blog readers a green tour of their campus today. In it we learned that the company actually rents goats to mow the fields of their Mountain View headquarters in California. Jen the border collie helps to herd them. No kidding.
  • TUAW, the unofficial Apple blog, advertized five apps to help save the world. They include “Pollution”, which pinpoints local pollutant sources in your area on an interactive map. And “Gas Cubby”, which helps you track your car’s miles per gallon, vehicle maintenance and sends reminders for things you can do to keep your car running more efficiently and burn less fossil fuels.
  • Fix the climate, or the kid gets it. In this entry, Mother Jones writes about what it’s going to take to get action on climate change. “You know the answer — we all do: It's going to take popular pressure, aka politicians feeling that they have to produce something on this issue to get reelected. And that, in turn, takes convincing Americans that something we care about is actually at risk here…And of course [that] something is…our kids.“
  • Speaking of politicians, British Prime Minister Gordon Brown blogged just after midnight on a similar theme: “Like every parent, I want to leave a safe and secure world for my children. And I want to be able to look them in the eye because our generation stood up for their future.” Brown says he will attend the December talks "if it means we will get an agreement, and I am urging other leaders to join me. But it must be the start of something not the end."
Let’s see what Copenhagen brings.

October 12, 2009, 17:00 PDT

Pick of the pics

Into the abyss: Dagze Co, Tibet

Courtesy of NASA/Goddard Space Flight Center, Japan's Ministry of Economy, Trade and Industry, Japan's Earth Remote Sensing Data Analysis Center, the Japan Resources Observation System, and the U.S./Japan ASTER Science Team.

Courtesy of NASA/Goddard Space Flight Center, Japan's Ministry of Economy, Trade and Industry, Japan's Earth Remote Sensing Data Analysis Center, the Japan Resources Observation System, and the U.S./Japan ASTER Science Team.

Dagze Co is one of many inland lakes in Tibet, with an area of about 260 square kilometers (100 square miles). In glacial (ice age) times, the region was considerably wetter, and lakes were correspondingly much larger. The numerous concentric rings that circle the lake are fossil shorelines, and attest to the presence of a larger, deeper lake in the past. Climate change since then has caused the Tibetan Plateau to become more arid, and its lakes to dry up. The picture was taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard NASA’s Terra satellite on October 8, 2001.

October 7, 2009, 17:00 PDT

The year without a summer

Peering through volcanic veils


From Erik Conway,
NASA Jet Propulsion Laboratory

In 1815, Mt. Tambora in Indonesia underwent the most deadly volcanic eruption in recorded history. The “super colossal” eruption, which measured 7 on the Volcanic Explosivity Index (VEI), pumped out enormous amounts of dust and ash, destroyed crops and vegetation, killed tens of thousands of people and even caused tsunamis.

A century and a half later, American oceanographer Henry Stommel and his wife, Elizabeth, published an article in 1979's Scientific American entitled “The Year Without a Summer.” They suggested that the eruption had caused a severe summertime cold snap during 1816 that resulted in killer frosts in New England and Europe. Soaring food prices and famine followed the frosts, to the degree that 1816 was also nicknamed “Eighteen Hundred and Froze to Death.”

The Stommels were revisiting an old controversy: can volcanic eruptions change the climate? The issue had first been taken up by scientists in 1901, when a pair of Swiss researchers proposed that the dust thrown up by a series of large volcanic eruptions could have caused the ice ages, by blocking out the Sun’s rays. However, they had no evidence to support their hypothesis. Despite the giant eruption of the island of Krakatau (perhaps more commonly known as Krakatoa) in Indonesia in 1883, and subsequent in-depth studies of the event, world temperature data hadn’t been collected.

The 1912 eruption of Mt. Katmai in Alaska motivated a number of others to probe the volcano-climate connection. Charles Greeley Abbott measured the sunlight reduction caused by Katmai’s eruption; William Jackson Humphreys, meanwhile, went back to the records of the Krakatoa and Tambora explosions. He concluded that Tambora was responsible for the subsequent cooling.

But Humphreys' argument wasn’t widely accepted. In the 19th century there was nothing like today’s global observation systems, so the data available to him were sparse. That made his conclusions rather speculative. The lack of volcanic eruptions between 1912 and 1963 then left the whole idea moot, since no new data meant nothing to study.

Scientists turned back to the subject of dust and climate following the invention of a kind of man made volcano — the hydrogen bomb — in the 1950s. The U.S. Defense Department funded studies of bomb effects on the climate until the Limited Test Ban Treaty of 1963 banned above-ground tests. NASA scientists picked up the baton and started investigating in the late 1970s, just in time for a whole series of large eruptions: Mt. St. Helens (1980), El Chichón (1982), and finally the 20th century’s largest, most destructive, and deadliest eruption, Mt. Pinatubo in 1991.

Reams of data from these explosions enabled us to come up with the answer: volcanic explosions do cause global cooling. Sometimes. Whether or not a specific eruption leads to cooling depends on its size, location and even chemical composition. But Tambora probably did cause the Year Without a Summer.

Erik is a historian based at NASA’s Jet Propulsion Laboratory in Pasadena, California.

October 4, 2009, 17:00 PDT

The acid test

Unveiling secrets of the deep

Fish and coral.

Hidden beneath the ocean are “worlds within worlds”, according to a new documentary from the National Resources Defense Council (NRDC). But these worlds could come crashing down as a result of ocean acidification, a problem that has only relatively recently come to light.

Ocean acidification describes the process by which our ocean has become more acidic — about 30 percent more — since the Industrial Revolution. About a quarter of the carbon dioxide (CO2) we pump out into the atmosphere every day through the burning of fossil fuels and other activities is absorbed by the seas. Sigourney Weaver, who narrates the video, asks, “What happens when so much CO2 — 22 million tons of it each day — mixes with ocean water?”

Scientists once thought this ‘mopping up’ process was beneficial because it reduces the amount of CO2 in the air that can cause global warming. But we now know that the uptake of CO2 can in fact alter ocean chemistry for thousands of years, and damage marine life in the process.

Ocean acidification interferes with the process of calcification, by which marine animals such as mollusks and crustaceans make cell coverings or skeletons from calcium carbonate. It has been implicated in causing coral reefs to lose their color (an effect known as “coral bleaching”). And more acidic seas can also affect phytoplankton and zooplankton, which are major food sources for fish and other sea creatures. All in all, a more acidic ocean could wipe out species, disrupt the food chain and hurt fisheries, tourism and other ocean-dependent industries. One study put the losses due to reduced U.S. mollusk harvests through 2060 at around $1.5—6.4 BN, although this did not include the hard-to-quantify knock-on job losses in affiliated industries.

Over the past 200 years, the pH of the oceans has dropped (i.e., become more acidic) by about 0.1 units on the pH scale. According to a recent Royal Society study, if we continue to pollute our atmosphere with CO2 as we are now, the average pH of the oceans could fall by 0.5 by 2100, a rate of change that is probably 100 times larger than at any other time in recent history. Ocean acidification is fast becoming a blip on researchers’ radar, with some calling it the “other carbon problem” (the first being global warming). In decades to come, Weaver explains, rising ocean acidity may challenge life on a scale that has not occurred for tens of millions of years. “We confront an urgent choice. To move beyond fossil fuels or to risk turning the ocean into a sea of weeds.”