climate

Updated 6-Feb-08. I frequently give talks on climate change and am often asked to share my presentation. Here is a recent one for download and use. If you use it, please let me know. Choose the appropriate format and spread the word about global climate change.

The talks are really intended for me to present, so there is very little text. I've tried to add some notes and references to help you. Contact me if you have any questions.

• PowerPoint 2008: Global Warming Talk Updated 6-Feb-08.
• Older versions of PowerPoint: Download

The files are zipped and approximately 30 MB in size, each.

In my first radio broadcast, and my first scientific debate, I went head-to-head with Roy Spencer, a famous global warming denier on the radio show Political Animals. You can listen to the show here. My part begins about 25 minutes into the show. I debate Roy Spencer for about 30 minutes. Then I am on for another hour with the hosts and callers.

This video was the winner of a contest to create a 60 second video on global warming. Check it out:

John Houghton was one of the chief science editors for the IPCC for the first 3 assessments. He is a devout Christian and is now giving lectures on why Christians should care for the environment (and that they are lagging behind other groups).

Houghton is one of the most respected climatologists alive today. He feels that all people have a responsibility to the wellbeing of the planet, and calls on Christians, especially, to help reduce the impacts of climate change. Here's a quote:

"Well, Christians believe that we have been put into the world to look after it and to care for the whole of creation. That's a message presented very early on in the Bible. Adam and Eve were put into a garden and they were told to look after that garden. That garden is Earth.
"Because of the enormous population we now have and the rapid development of technology, we are putting pressure on resources, and our care of the Earth is very far from what it should be. We should pay much more care to looking after the Earth in a sustainable way. The simplest definition of sustainability that I know is not cheating on our children, not cheating on our neighbors, or the poor people in the world, who stand to be very disadvantaged by things like climate change. And also not cheating on the rest of creation. We are in danger of losing thousands, if not millions, of species because of climate change.
"Of course, it's a very broad human responsibility, not just a Christian one. But on the whole, Christians have been lagging behind many other groups in their concern for the environment, care for the Earth, and care for poor people. And Christians, because of their beliefs, should really be out in front."

Read the full article and interview of John Houghton.

I often read the "Quotation of the Day" from the New York Times. Today's was rather poignant.

"This is the first year we’ve competed with the beaches." Carol Olsen, director of the Rockefeller Center ice rink, the famous ice rink in the middle of New York City, said yesterday, as the rink opened for the season, "This is the first year we’ve competed with the beaches."

Long-term forecasts suggest that this record-breaking warm spell is due to end and temperatures should drop to more-normal levels later this week. This is likely to be (according to those forecasts) the last really warm spell of the season.

The Alliance for Climate Protection just put out this is a great video helping us visualize our personal contribution to global warming. Watch:

Last month, over 600 people posed naked on the Aletsch Glacier near Bettmeralp, Switzerland for photographer Spencer Tunick to raise awareness of global climate change. Watch the video: Spencer is known for his photography of large groups of naked people in public settings. Most recently, he had photo shoots in Amsterdam and Mexico City.

Research that I've been involved in on the Greenland Ice Sheet was featured in NASA's Earth Observatory this week. The story provides an overview of recent melting on the ice sheet, the warming that is causing it, and the projected resulting sea-level rise. Photos highlight some of the magnificent and also daunting conditions that we face on the ice sheet.

Read the article here.

What is surprising is that this new record comes a month early. The ice is still melting! The frozen layer of sea ice that covers much of the Arctic Ocean, including the North Pole, expands and contracts with the seasons in the Northern Hemisphere. In Winter, the ice cover grows dramatically, reaching a maximum extent in early Spring. In the warmer months, however, the over-extended ice cover retreats to cooler climes, reaching it's smallest extent in mid-September, as show by the solid black line in the chart below.

Arctic sea ice, unfortunately, is one of the major victims of global warming. On August 9^th, 2007, a record low in the extent of Arctic sea ice was recorded (cyan line above), beating out the previous record low of 2005 (dashed green line above). This is not surprising in light of the Arctic's unfair share of climate change. What is surprising is that this new record comes a month early. The ice is still melting!

Below are two images comparing sea-ice concentrations (denser sea ice has fewer leads, or breaks in the ice, and is usually thicker) from the minimum extent in 1979 to the extent on August 9^th.

The trend in Arctic sea ice has been dramatic, as illustrated in the following chart.

Finally, the map below shows the sea-ice extent in August (white) compared to the median Julie sea-ice extent (magenta line).

All of this is in the context of rapid climate change. One measure of global temperatures, produced by NASA GISS, was recently updated and, unlike other similar records, includes the Arctic. The figure follows.

In order for tropical storms to strengthen into hurricanes, they need two main ingredients -- warm water and moderate upper-level winds. Satellite imagery provide excellent measures of sea surface temperatures, indicating how the region of hurricane formation in the North Atlantic, Caribbean, and Gulf of Mexico are at ideal temperatures for storm formation.

Of course, the Atlantic isn't the only region susceptible to tropical cyclones (we just don't call them "hurricanes" elsewhere). The map below shows additional warm areas of water, ideal for the formation of these storms. Too close to the equator, though, the storms won't form because of the weak Coriolis effect there.

Note the unusually cool water along the equator in the eastern Pacific, off the coast of South America. This cold water allows penguins to thrive in the Galapagos Islands and also controls global climate in many ways. When this water warms, we call it an El Niño event.