365 Days of Climate Awareness 149 – 2008 State of the Climate, North America and Europe

2008 US Climate Data

• Global atmospheric CO₂ concentration: 385.02 ppm, +2.12 ppm from 2007
• Average air temperature: 54.2°F, 48^th all-time 1895-2021
• Average precipitation: 28.4”, 45^th wettest (83^rd driest) 1895-2021
• Tornadoes: 2192, 922 (73%) above the ten-year average 1270
• 16 named tropical cyclones: 8 became hurricanes, 5 major (winds > 111 mph, 3-5 Saffir-Simpson)
• Atlantic ACE: 142 x 10⁴ kts²
• ENSO: La Niña through July; neutral through November; La Niña through year’s end

North American & European Conditions

• Warmer than average: Southwestern & northeastern US; Canada; Mexico; Europe
• Cooler than average: Midwestern US
• Drought: Western US
• Above-average precipitation: Midwestern US; Ontario; Quebec
• Wildfires: Below average; intense in southwest and southeastern US

Snowfall, though below average for the continent as a whole, was above average in the Rockies, though parts of Wyoming, Montana, Nevada and north-central Washington received less. The northeastern US faced a serious of intense late-winter storms. The very active hurricane and tornado seasons were abetted by a strong La Niña through much of the year. It featured Hurricane Ike, which struck Cuba as a category 4 (130-156 mph sustained wind speed) and then Texas as a category 2 (96-110 mph), doing an estimated $30B of damage, the third-costliest (now sixth) hurricane to date.

The ENSO cycle has a large influence on Northern Hemisphere temperatures. Heat flux from warm El Niño surface water leads to warmer air temperatures, and cooler surface water with La Niña causes the air to cool. In this way ENSO is one of the, if not the most dominant sea-air heat cycle in the climate system. North America experienced a cooler-than-average winter during the strong La Niña winter, but summer was warmer on average during the neutral phase.

Along with the rest of the region, Arctic Canada was significantly warmer than average, with a continued trend toward earlier and more sustained melting. Ground temperatures across Alaska and Canada show an increase of 1-2°C in the permafrost. 2008 Arctic ice cover was the second-lowest on record, and 36% below the 1979-2000 average. A large section of the northern coast of Ellesmere Island was ice-free for the first time in recorded history. Observations at this time confirmed that severe sea ice loss, by loss of the ice’s albedo, contributes directly to Arctic ocean warming, to its increasing stratification and further ice loss.

Tomorrow: 2008 State of the World Climate.

Be brave, and be well.