The One Degree World
"The One Degree World" is a term, derived from Mark Lynas' book on the impacts of global warming, describing the world at one Celsius degree above pre-Industrial temperatures. Since global mean temperature has increased between .7-.8 degrees C, we are living in a "one degree world" now.
Some of the changes described have been seen, or are beginning to be seen; others may come about in the future, even if future warming is somehow held in check--unlikely to impossible, according to what we know about the physical mechanisms involved in the planet's 'heat budget'. In other words, some effects (similar to a loaf of bread baking in the oven) may not need more warming, just more time to 'cook.'
The impacts are described in tabular form below, according to notes made from the "One Degree" chapter of Lynas' book. Six Degrees was published in 2008, so updates will be added where appropriate--and as I can find opportunities to do so!
America's Slumbering Desert, p. 25
Medieval North American megadroughts could return, creating a perennial--and much worse--'Dust Bowl.'
Already The Day After Tomorrow?, p. 31
Possible Western European cooling due to weakening of the Meridional Overturning Circulation (of which the Guld Stream is the best-known aspect) is unlikely to do more than ameliorate overall climate warming--*not* create a new ice age, as in the Hollywood movie.
Africa's Shining Mountain, p. 35
Kilimanjaro's glaciers are disappearing, as are most other tropical glaciers; but the biggest impact on ecosystems in the region of Kilimanjaro will be from mid-altitude deforestation. Elsewhere, though, the loss of glacial meltwater may be a serious problem.
Ghost Rivers of the Sahara, p. 40
The fringes of the Sahara were moister once; some models suggest the Sahel (the southern flank of the Sahara) may become moister and somewhat more hospitable.
The Arctic Meltdown Begins, p. 46
The 'tipping point' concept, Arctic amplification, sea ice and its decline, and the jet stream.
Danger in the Alps, p. 51
Alpine rockfall and landslide in the 2003 heatwave; the 2003 experience as portent for the one degree future.
Queensland's Frogs Boil, p. 54
Wide-spread threats to diversity: Endangerment in Australia's "Wet Tropics" UNESCO site; coral bleaching; Cape Floristic, SA, flora endangered; pikas in western US. The Golden Toad of Costa Rica extinct due to climate change (1989), the first of more than 100 frog species to be lost.
Hurricane Warning in the South Atlantic, p. 64
Climate change alters storm tracks: Hurricane Catarina was the first to form in the South Atlantic, and the first ever to strike Brazil (2004.) Hurricane Vince was the first to strike Europe when it made landfall in Spain in 2005.
Sinking Atolls, p. 69
Tuvalu, the Maldives, and other island nations at risk due to sea level rise. In all, about half a million people inhabit the five nations. "...in all probability, nothing can save the Pacific island of Tuvalu... seas will go on rising for centuries even if all greenhouse gas emissions stopped tomorrow."
Go to main article on "Six Degrees."
- Mark Lynas's "Six Degrees": A Summary Review
"Six Degrees" is a modern classic, outlining potential effects of various levels of global warming. It's summarized, evaluated, and updated here, with links to 7 supplementary Hubs.