Dangerous Catch Dirty Secrets Additional Episodes
TV Schedules About the Project For Educators Feedback border
National Geographic's Strange Days on Planet Earth
Get Involved
Little changes... with big results. border
border Why Should I Care? border border

6 Reasons Why

Why Others Care
border What Do Experts Say? border border

From the Episode

Related Stories

border How Do I Measure Up? border border

Tools You Can Use

Interactive House
border What Can I Do? border border

Get Out There

Idea Exchange

Please note that links marked with Off-site Link are off-site links and will open in a new browser window.

PBS's Terms of Use.

One Degree of Difference

What makes you most hopeful for the future?
Somero: “There are young people growing up who can see through all of the distortions thrust upon them by the media, notably the misinformation we're currently flooded with to the effect that "everything is just fine with the environment" and we needn't worry a bit about global warming...”

See George Somero's full Q&A »

What makes you most fearful for the future?
Stillman: “What makes me the most fearful is how increasing human populations will continue to impact the planet...”

See Jonathon Stillman's full Q&A »

The impact of rising temperatures on animal and plant life is being measured across the world. Numerous studies are documenting latitudinal shifts in wildlife populations on land and sea from butterflies to sea snails.

In California tide pools, similar changes are being witnessed as southern species progressively move into more northern reaches, driven by warming.

Research studies indicate some species may be subjected to severe physiological stresses before they relocate. Physiologists George Somero and Jonathon Stillman are studying how a simple one-degree change in temperature could affect the intertidal porcelain crab. In an experiment to test the thermal tolerance of these crabs, Stillman hooked up the small animals to a heart rate monitor, immersed them in water and gradually increased the temperature. He discovered that those crabs currently experiencing the biggest daily temperature swings are already just about at their limit. Their hearts stop beating in water only two degrees Fahrenheit warmer than what they currently experience in the wild. With global warming increasing, these crabs are edging ever closer to their absolute limits.

Related Links
» To see a dramatic visualization of how climate change may affect the Great Lakes region of the U.S over the coming century, visit Migrating Climates Off-site Link —part of the Union of Concerned Scientists website.
» A comparative analysis of the upper thermal tolerance limits of eastern Pacific porcelain crabs, Off-site Link genus Petrolisthes: Influences of latitude, vertical zonation, acclimation and phylogeny by J. Stillman and G. Somero.
» More information on animal and plant movements in response to global warming.

Next: Asthma, Coral and African Dust »

Site Credits   |   Privacy Policy
© Copyright National Geographic Television & Film. All rights reserved.