Global Warming: It’s Later Than We Think…But It’s Not Too Late

1. Global Warming: It’s Later Than We Think…But It’s Not Too Late Anthony J. Broccoli Director, Center for Environmental PredictionDepartment of Environmental Sciences Rutgers University Pulse of the Planet Lecture SeriesLiberty Science Center, Jersey City, NJJanuary 26, 2008

3. Temperatures in the New York City area in the past 30 days have been:a) more than 2°F below normalb) within 1°F of normalc) about 3°F above normald) more than 6°F above normal

4. Temperatures in the New York City area in the past 30 days have been:a) more than 2°F below normalb) within 1°F of normalc) about 3°F above normald) more than 6°F above normal

5. Source: NOAA Climate Prediction Center

6. Source: NOAA Climate Prediction Center

11. “The unequivocal detection of the enhanced greenhouse effectfrom observations is not likely for a decade or more.” Climate Change – The IPCC Scientific Assessment (1990) “The balance of evidence suggests a discernible human influence on global climate.” Climate Change 1995 – The Second Assessment of the Intergovernmental Panel on Climate Change (IPCC) “Most of the observed warming over the last 50 years islikelyto have been due to the increase in greenhouse gas concentrations.” Climate Change 2000 – The Third Assessment Report of the IPCC “Most of the observed increase in globally averaged temperatures since the mid-20th century isvery likelydue to the observed increase in anthropogenic greenhouse gas concentrations.” Climate Change 2007 – The Fourth Assessment Report of the IPCC

12. The IPCC’s conclusion that the observed warming is very likely due to increasing greenhouse gases an that further warming is on the way is based on:a) laboratory measurementsb) results from computer modelsc) climate observations d) all of the above

13. The IPCC’s conclusion that the observed warming is very likely due to increasing greenhouse gases an that further warming is on the way is based on:a) laboratory measurementsb) results from computer modelsc) climate observationsd) all of the above

14. What Are Climate Models?

15. “It is extremely unlikely that global climate change of the past fifty years can be explained without external forcing.” Blue: NaturalPink: Natural + Human-induced

16. Projections of Future Climate Variations among colored lines represents uncertainty due to uncertainty in future emissions.

17. Simulating Future Climate Change Source: NOAA Geophysical Fluid Dynamics Laboratory

18. Potential Climate Change Impacts

19. Global Impacts of Climate Change Report by IPCC Working Group II on Impacts, Adaptation and Vulnerability was released on 6 April 2007. Some of the highlights from this report: • There will be some winners, but more losers • Densely populated coastal regions will face increased pressures from sea level rise and more extreme weather • Poor communities and stressed ecosystems will suffer most, as they are already living “on the edge” • 60% of world’s species are already responding to change

20. Global Impacts of Climate Change Report by IPCC Working Group II on Impacts, Adaptation and Vulnerability was released on 6 April 2007. Some of the highlights from this report: • There will be some winners, but more losers • Densely populated coastal regions will face increased pressures from sea level rise and more extreme weather • Poor communities and stressed ecosystems will suffer most, as they are already living “on the edge” • 60% of world’s species are already responding to change

22. Sea Level Trends in New Jersey Atlantic City, NJ Source: National Oceanic and Atmospheric Administration NJ sea level rise = global sea level rise + other effects0.4 m/century = 0.16 m/century + 0.24 m/century

23. Why is global sea level rising?a) the density of the ocean is decreasingb) sea ice is melting rapidlyc) mountain glaciers are meltingd) the Greenland and Antarctic ice sheets are melting

24. Why is global sea level rising?a) the density of the ocean is decreasingb) sea ice is melting rapidlyc) mountain glaciers are meltingd) the Greenland and Antarctic ice sheets are melting

25. Why Is Global Sea Level Rising? • Thermal expansion Warmer water is less dense than colder water. • Melting of glaciers and ice caps Water released by the melting of ice on land adds to the volume of the oceans. • Melting and calving of Greenland and Antarctic ice sheets Depends on the ice sheet dynamics (how the ice flows).

26. Why Is Global Sea Level Rising? • Thermal expansion Warmer water is less dense than colder water. • Melting of glaciers and ice caps Water released by the melting of ice on land adds to the volume of the oceans. • Melting and calving of Greenland and Antarctic ice sheets Depends on the ice sheet dynamics (how the ice flows).

27. Why Is Global Sea Level Rising? • Thermal expansion Warmer water is less dense than colder water. • Melting of glaciers and ice caps Water released by the melting of ice on land adds to the volume of the oceans. • Melting and calving of Greenland and Antarctic ice sheets Depends on ice sheet dynamics (how the ice flows).

28. 0.61 m (2 ft) sea level rise by 2100—middle of the road estimate. 1.22 m (4 ft) sea level rise by 2100—more melting from Greenland/Antarctica Effects of Sea Level Rise on the Coastal Environment Land area susceptible to inundation Land area susceptible to coastal flooding (“30-yr flood”) Source: M. D. Beevers, U.S. Climate Change Science Program Workshop, Nov. 2005

29. “Ash Wednesday Storm” Harvey Cedars, March 1962

30. New Brunswick, April 16, 2007John Munson/The Star-Ledger

31. Flood Stage 3 of 7 largest floodssince 2004

32. Warmer↓ MorePrecipitation Warmer↓ MoreEvaporation

33. New Brunswick, April 16, 2007John Munson/The Star-Ledger “…there is an increased chance of intense precipitation and flooding due to the greater water-holding capacity of a warmer atmosphere. This has already been observed and is projected to continue because in a warmer world, precipitation is concentrated into more intense events…” IPCC Fourth Assessment, 2007

34. days per year over 90ºF days per year over 100ºF IPCC: “It is very likely that hot extremes, heat waves, and heavy precipitation events will continue to become more frequent.” Changes in number of days with heat waves from UCS Northeast Climate Impacts Assessment

37. Future Emissions Scenarios Some scenarios showdecreased emissionsin latter half of 21stcentury Even with aggressivereductions in emissions,CO2 would rise to 2xpreindustrial levels All scenarios showincreasing emissionsduring next severaldecades

38. More Warming in the Pipeline Future emissions Additional “zero-emission” warming (aka “commitment”) Warming to date

39. Psychological Barriers? • Climate change is not the result of malevolence. • Climate change does not violate our moral sensibilities (i.e., cultural taboos). • Climate change is perceived as a future rather than an immediate threat. • Climate change proceeds gradually. Source: Daniel Gilbert, Harvard University, Los Angeles Times, July 2006

40. What actions would you favor for reducing the threat of climate change?a) increase energy efficiencyb) capture and sequester CO2 from fossil fuel burningc) increase nuclear power generationd) build more wind turbines and solar power systems

41. What actions would you favor for reducing the threat of climate change?a) increase energy efficiencyb) capture and sequester CO2 from fossil fuel burningc) increase nuclear power generationd) build more wind turbines and solar power systems

42. “Wedges” Billion of Tons of Carbon Emitted per Year 14 14 GtC/y Currently projected path Seven “wedges” O Historical emissions 7 GtC/y 7 Flatpath 1.9  0 2106 1956 2006 2056 Source: S. Pacala and R. Socolow, Princeton Univ.

43. Natural Sinks CCS Nuclear Efficiency Renewables 15 Different Technologies Already in the Marketplace at Industrial Scale Coal to Gas

44. The Global Warming Dilemma(J. Mahlman, In Solutions for an Environment in Peril, 2002) “There are no quick policy fixes, nationally or globally. If we don't begin to chip away at the problem soon, it is very likely that serious consequences will be wired in for the world of our great-grandchildren and for their great-grandchildren.... The long time scales and robustness of the problem almost guarantees that our descendants in the 22nd century will, with historical perspective, see that we were actually confronted with a major planet-scale stewardship/ management problem. They will most assuredly note how we responded, or how we did not respond to the problem.”

46. The climate is changing…

47. Why Is Global Sea Level Rising? Melting Glaciers and Ice Caps: Water released by the melting of ice on land adds to the volume of the oceans.

49. Global Warming and the Hydrologic Cycle • The downward flux of radiative energy (i.e., sunlight and infrared radiation) at the surface is balanced by evaporation and sensible heating of the atmosphere. • If the downward flux of energy increases, then evaporation will increase. • On a global basis, evaporation and precipitation must balance. • Thus as the earth warms, both evaporation and precipitation will increase.

50. Warmer↓ MorePrecipitation Warmer↓ MoreEvaporation