CLIMATE AND LAND USE CHANGE IN PACIFIC MESOAMERICA

1. CLIMATE AND LAND USE CHANGE IN PACIFIC MESOAMERICA CHALLENGES FOR CONSERVATION OF BIODIVERSITY AND SUSTAINABLE DEVELOPMENT

2. Content • The global picture • Scenarios for Costa Rica and Central America • What are the challenges for conservation? • What are the opportunities for rational responses?

3. Industrial revolution and the atmosphere The current concentrations of key greenhouse gases, and their rates of change, are unprecedented. Carbon dioxide Methane Nitrous oxide

4. Temperature change C • 85% of world’s glaciers are retreating. • The majority of Greenland and Antarctica ice caps melting twice as fast as expected. • 0.5 degree C rise in SST= 40% increase hurricane activity.

7. Climate Change Changes in the mean (average) and variance …are both important for temperature and rainfall

8. …new considerations • El Nino Modoki • African dust • Trace gases • Clouds

10. EL NINO June, July, August Hot and Dry in Costa Rica December, January, February typical hot and dry in Costa Rica (northern Pacific side)

11. Sea surface temperatures (SST) of classic developing El Nino

12. High wind shear in Caribbean reduces formation of strong storms. A characteristic feature of El Nino years.

13. El Nino Modoki or Central Pacific El Nino During an El Nino Modoki, the Pacific warm pool is further westward. Wind shear in the Caribbean is reduced and the formation of strong Atlantic storms may increase. Greater ocean productivity in the Costa Rica “dome”?

14. And the role of African dust??Most comes from a small part of Mali

16. Will the Sahelian climate become drier or wetter…climate models give contradictory scenarios. But…. Overgrazing by goats is increasing dust storms in Africa.

19. Trace gases emitted by vegetation may also be important Isoprene and monoterpense (volatile organic compounds) may make up as much as 6% of atmospheric carbon

20. Tropical forests emit the largest amounts of isoprene and monoterpenes

21. Organic aerosols, especially monoterpenes, contribute to cooling of the atmosphere. They can form raindrop nuclei and increase rainfall. Important in coniferous forests where mostly monoterpenes are emitted. However….in tropical forests both isoprene and monoterpenes are produced. And more are produced at higher temperatures.

22. Large air chamber experiments demonstrate that rain nuclei do not form from these aerosols when isoprene and monoterpene occur together.

23. Increasing amounts of isoprene plus monoterpene may therefore lead to drier and warmer conditions. Will this be true in the real tropical environment? Forest composition will be important because some species emit mostly isoprene, e.g. Quercus, while others emit mostly monoterpenes, e.g., Eucalyptus, Anacardium.

24. Do clouds (red) above warm oceans act to cool or to warm the atmosphere? Results of 55 year study of ship records recording ocean temperature and cloudiness suggest that low level “cooling” clouds are dissipated and there is an increase in high level clouds that allow more sunlight penetration. Therefore, high level clouds forming over warm oceans may act as a positive feedback mechanism to enhance further warming.

25. The Working Group I Report IPCC 2007 • Started 2004 • Completed February 2007 • 152 Authors • ~450 contributors • ~600 expert reviewers • 30,000+ review comments • And, that is just for this Working Group http://ipccwd1.ucar.edu/

31. What do the regional climate models tell us?

32. Regional climate models Consider such local variables as mountains, proximity to ocean, land use, etc.

36. Regional Climate Model (CATHALAC 2008)

37. Precipitation

38. Future climate of Costa Rica…best guesses

39. Scenarios for Costa Rica and Central America • Even more uncertainty • General agreement that the future will be hotter and drier than the present • Likely that much of Central America will have more prolonged droughts • Plausible that much of Central America will have few but more intense storms

40. Some likely consequences for Costa Rica

41. Possible increase in vector borne diseases

44. Tiger mosquito (Aedes albopictus) distribution

45. Aedes albopictus

47. Challenges for conservation • Changes in species distribution and abundance • Altered phenology and productivity of forests • Vulnerable aquatic ecosystems • Re-assessing environmental services

48. Changes in species distribution and abundanceSome examples at small, medium and large scales

49. Fig trees are pollinated by small wasps that fly short distances. Because fig trees reproduce asynchronously and are abundant there is usually a nearby fig to pollinate. However, drier and hotter weather may reduce flight distances and affect fruiting patterns

50. Quetzal and Lauraceae distribution with climate change???Quetzal migrate up and down mountains following the fruiting pattern of several species of Lauraceae.