In March 2007, we blogged about the dire situation of the South Pacific islands Kiribati and Tuvalu. The sea is rising due to global warming, and two uninhabited islands nearby have already sunk. Now Kiribati is preparing for extinction:

The leader of the South Pacific island nation of Kiribati laid out an extraordinary plan Monday (Sept. 22) that would scatter his people through the nations of the world as rising sea levels submerge the islands they have called home for centuries.

Rising sea levels are submerging the land. Land not yet submerged is being rendered uninhabitable by salty ground water.

This post is by Sheryl Canter, an online writer and editorial manager at Environmental Defense Fund.

Last Thursday, the Global Carbon Project released its annual report on the state of the carbon cycle, Carbon Budget 2007 [PDF]. It emphasizes (as we reported earlier this year) that CO₂ levels are continuing upward, and the rate of increase is accelerating.

One reason for the acceleration in CO₂ concentrations is higher fossil fuel emissions. Despite rising fuel prices, global CO₂ emissions from fossil fuels rose 3 percent in 2007. That's just slightly below the average increase of 3.5 percent per year since 2000.

Read more »

There was an interesting story in Tuesday's New York Times about a unique weather station in upstate New York next to the Mohonk House resort. Most cooperative observer stations move over time, or the area around them is built up, or the observers and observing methods change. Not so at Mohonk.

At Mohonk, the weather observations are done as they were 112 years ago, and only a handful of people have recorded the over 41,000 readings. Plus Mohonk has an extensive database of wildlife sightings, a 77-year record of Mohonk Lake water quality, and an 83-year record of local phenology (the timing of events such as frost, blooms and migrations) - all observed by the same handful of people. This makes the site's data uniquely valuable:

Read more »

This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

Have you ever spent time scrolling through NASA's image gallery? Some of the pictures are mesmerizing. I particularly like the "Blue Marble" image of the Earth (at right), which was stitched together using satellite data.

Satellites provide more than pretty pictures. Our ability to understand and predict climate change depends on continuous high-quality satellite data.

Unfortunately, this critical data stream is threatened by budget cuts and lack of political support. In 2005, the National Academies assessed the situation and deemed it "alarming". Three years later, the outlook has not improved.

Read more »

This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

In 1992, the world's nations gathered to negotiate the United Nations Framework Convention on Climate Change. The 192 nations that ratified this treaty - including the U.S. - agreed to the following objective:

[T]o ... prevent dangerous anthropogenic interference with the climate system… within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.

The definition of "dangerous" is a social and political judgment that is informed by science. But even if we all agreed on which outcomes we wanted to avoid, scientists couldn't say precisely how much we have to cut emissions to achieve these outcomes. We have good best estimates, but there's always a degree of scientific uncertainty.

Here's why.

Read more »

This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

IPCC scientists have been saying for years that man-made global warming is likely to increase extreme weather events. A new report ("Weather and Climate Extremes in a Changing Climate") from U.S. government scientists confirms these findings, and focuses specifically on the U.S.

It's certainly timely, considering the devastating floods in the Midwest.

Read more »

This post is by James Wang, Ph.D., a climate scientist at Environmental Defense.

The record floodwaters in Iowa and other parts of the Midwest are claiming lives, destroying homes and crops, contaminating drinking water, and - as the AP puts it - spreading "a noxious brew of sewage, farm chemicals, and fuel that could sicken anyone who wades in." The cost in human anguish is incalculable.

But why is it happening? Is it just a freak of nature? One causal element, as reported in today's Washington Post, may be human reengineering of the landscape. Mary Kelly, who heads up EDF's rivers and deltas program, gives a good overview of these issues.

Another element may be global warming, which increases the probability of extreme weather events like torrential rain.

Read more »

This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

In IPCC's Third Assessment Report (2001), scientists reported that carbon dioxide (CO₂) and methane levels were higher than at any time in the past 420,000 years. In their latest report (2007), IPCC scientists raised the number to 650,000 years.

Last week, scientists again revised the number upward. New research shows that CO₂ and methane levels are higher today than they have been in at least 800,000 years.

Here's how they know.

Read more »

This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

An article in this week's Nature predicts that Europe and North America will cool slightly over the next decade. No, this doesn't mean that global warming has stopped.

The new paper describes a climate model that makes short-term (decadal) predictions based on ocean dynamics. The decade-long cooling is just a temporary offset to warming from human activity. After it passes, temperatures will begin climbing again. By 2030, the model forecasts the same global temperatures as the IPCC.

This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

Last week, NOAA released some disheartening numbers: both CO₂ and methane increased sharply last year. Growth rates are increasing (see graph to the right).

The CO₂ numbers weren't a surprise. A paper with similar findings was published last November by a team that included a NOAA scientist. I wrote a blog post summarizing the study, which analyzed the reasons behind the trend (see Rise of Atmospheric Carbon is Accelerating).

The methane numbers, however, were disturbing. Until this year, methane levels have been essentially unchanged since 1998.

Read more »