1. LATEST UPDATE ON CLIMATE CHANGE
Steven W. Running
Numerical Terradynamic Simulation Group
University of Montana
NOVEMBER , 2005

2. Intergovernmental Panel on Climate Change, 2000
Global Warming
Intergovernmental Panel on Climate Change, 2000
“The Earth’s climate system has demonstrably changed
on both global and regional scales since the pre-industrial era,
with some of these changes attributable to human activities.”
American Geophysical Union, 2003
“Human activities are increasingly altering the Earth’s climate”

4. Dai et al. J. Hydromet (2004)

5. CLIMATE TRENDS for the last century

7. Temperature Trends: 1901 to 1998
Red circles reflect warming; Blue circles reflect cooling
All Stations/Trends displayed regardless of statistical significance.
Source: National Climatic Data Center/NESDIS/NOAA

8. Precipitation Trends: 1901 to 1998
Blue circles reflect increasing precipitation; Red circles reflect decreasing
precipitation
All Stations/Trends displayed regardless of statistical significance.
Source: National Climatic Data Center/NESDIS/NOAA

9. “Simulations of the response to natural forcings alone … do not explain the warming in the second half of the century” SPM
Stott et al, Science 2000

10. “..model estimates that take into account both greenhouse gases and sulphate aerosols are consistent with observations over this period” SPM
Stott et al, Science 2000

11. Aircraft Contrails, Jan 29 2004 MODIS
Contrail clouds warmed Earth 0.2degC/decade. Minnis, 2004

12. OBSERVED EARTH SYSTEMS RESPONSES

13. Global ocean circulation
Cooling
Warm
surface
current
Intermediate
waters
Warm and less saline
Antarctic circumpolar current
A simplified view of the global thermohaline conveyor belt, showing cooling and downwelling in the North Atlantic, warming and freshening in the southern hemisphere, and return flow as a warm surface current.

14. [1979 – 2002]

15. Comparison of the heat balance of the climate system Levitus et al (2001). Science Vol. 292, pp. 268.

17. Increase in Hurricane Intensity
PDI = Potential Destructiveness Index
Emanuel, Nature 4 August 2005

18. Increase in Category 4-5 Hurricanes 1970 - 2004
Webster et al, Science, Sept

19. Webster et al Science
Sept 16, 2005

20. Arctic sea ice gets thinner

22. From SMMR data

23. Montana = 0.38million km2
National Snow and Ice Data Center

24. Montana = 376,000km2

25. ALASKAN GLACIER MASS BALANCES 1950 - 2001
Arendt et al Science.

26. Antarctic
Glaciers
Cook et al Science

27. The South Cascade glacier, Washington
1928
Other evidence for warming comes from glaciers.
These pictures show the South Cascade glacier in 1928 and The glacier has retreated and thinned substantially, leaving a glacial lake in its place. Glacial retreats have occurred around the world.
Courtesy of the USGS glacier group
2000

32. Flood

33. Percent of the continental USA with a much above normal proportion of total annual precipitation from 1-day extreme events (more than 2 inches or 50.8mm)
BW 7
Karl et al. 1996

34. OBSERVED BIOSPHERIC
RESPONSES

35. Spring bud-burst dates for Aspen in Edmonton, Beaubien and Freeland I
Spring bud-burst dates for Aspen in Edmonton, Beaubien and Freeland I.J.Biomet 44:53-59, 2000

36. The increase in growing season length over the last 50 years averaged for eight stations in Alaska having the longest and most consistent temperature records.

38. Change in Terrestrial NPP from 1982 to 1999.
Nemani et al., Science June 6th 2003

39. BLEACHING OF CORAL REEFS BY OCEAN TEMPS > 85deg

40. Locations of Coral Reef Bleaching

41. CHANGE IN OCEAN NPP [1979 – 2002]

43. Human Mortality Attributable to Climate Change thru 2000 (heat stress, malnutrition, malaria, flooding, etc.)
Patz, et al Nature 438: , 2005

44. MISSOULA CLIMATE TRENDS SINCE 1950

51. Decrease Increase
Manual snow course measurements have been taken since the 1920s in a few places. Around April 1 the most common time of year.
Trends at most locations are negative. Largest decreases are generally at lowest elevation, especially in the Oregon Cascades.
the declines in snow occur in spite of increases in precipitation.
These results from Mote, P.W “Trends in Snow Water Equivalent in the Pacific Northwest and Their Climatic Causes”, Geophysical Research Letters (in press).
Mote 2003(b)

52. Trends in timing of spring snowmelt (1948-2000)
Yet another piece of evidence of warming came from this paper (Cayan et al., Bulletin of the American Meteorological Society, 2001). The timing of peak spring snowmelt (and of biological events like blooming and leafing-out dates of plants) has tended toward earlier dates over the last 50 years. These dates are highly correlated with spring temperature.
+20d later
–20d earlier
Courtesy of Mike Dettinger, Iris Stewart, Dan Cayan

53. INCREASING WILDFIRE IN CANADA
Gillette et al 2004

54. Projected PNW Climate Trends
Projected changes in average annual PNW temperature and precipitation for the decades of the 2020s and 2040s.
2020s
Temperature
Precipitation
Low
+ 0.9°F
+ 2 %
Mean
+ 2.4°F
+ 7%
High
+ 3.4°F
+ 14 %
2040s
Temperature
Precipitation
Low
+ 2.7°F
- 3 %
Mean
+4.0°F
+ 7%
High
+ 4.9°F
+ 14 %
Looking at what 8 models say for the Pacific Northwest, with a simple CO2 scenario (increasing 1%/year) the average of the changes is about 0.45C/decade with slight increases in precipitation. Precipitation is more difficult to simulate well, so we have less confidence in projections of future precipitation than in projections of future temperature.
Based on an increase in equivalent CO2 of 1% per year. Benchmarked to the decade of the 1990s.

55. THE S.W. RUNNING CRYSTAL BALL, MONTANA FOR THE NEXT 50 YEARS
EXPECTED MONTANA CLIMATE TRENDS
Shorter, milder winters
Earlier snowmelt
Longer growing seasons
Decreasing summer streamflows
More drought and fire danger
Precipitation???

56. EXPECTED MONTANA ECOSYSTEM TRENDS
- Earlier crop planting dates
More forest/range/crop productivity
Decreased deer/elk winterkill
Hibernating animals?
Increased forest insect/disease trends
More aquatic ecosystem degradation,
low dissolved O2, high water temps
More aquatic recreation limits

58. China Smog, Nov 4, 2005

60. Variations of the Earth’s surface temperature; 1000 to 2100