Tropical Deforestation and Climate Change: What Does the Record Reveal?

Abstract

Tropical deforestation is widely believed to directly influence the climate at a number of scales. Yet while much has been written about the tropical forest-climate relationship, there is little empirical evidence showing if and how local and regional climates are modified by deforestation. This study presents the results of an analysis of deforestation and climate change in a rain forest in southern Mexico. Records from 18 climate stations in the Selva Lacandona of Chiapas, Mexico were examined and related to an analysis of deforestation based on Landsat images. The area surrounding some stations has been deforested since the stations were established, while the area surrounding others has remained forested. Strong climatic trends were generally evident at the deforested stations, including decreases in the average daily maximum temperature and temperature range. No precipitation changes were observed. A comparison of the results with microclimatic experiments and modeling studies suggests that the climatic impacts of deforestation are overgeneralized at the local scale. Landscape heterogeneity appears to influence the biophysical mechanisms linking tropical forests and climate, and should be explicitly represented in modeling studies.

Problems in evaluating regional and local trends in temperature: an example from eastern Colorado, USA

“…Lewis (1998), for example, has found about a 1°C annual average increase in ground surface temperature at two closely spaced locations in western Canada when a site is locally cleared of forest. O'Brien (1998) found decreases in the average daily maximum temperature and temperature range when locations in southern Mexico were deforested.…”

Methodology in Climatology

“…• A perceived increase in the occurrence of both extreme weather (e.g., tropical cyclones, tornadoes, heat waves) and climate anomalies (droughts, extended wet periods), as well as decade-scale changes in temperature and precipitation (e.g., Parker and Folland 1988;Jones et al 1999). • A growing awareness of the potential and real impacts of human activities in some climate changes (Cotton and Pielke 1995), including "global warming" due to increases in trace ("greenhouse") gases; emissions of chlorofluorocarbons (CFCs) and their effects on the stratosphere's ozone layer; land-cover modifications, particularly deforestation and conversion to agriculture, urbanization, and large-scale irrigation; tropospheric air pollution, particularly the emissions of sulfate aerosols; and cloud-cover increases, especially in regions of heavy jet air traffic (e.g., Changnon 1981Changnon , 1992Karl et al 1988Karl et al , 1991Hunter et al 1993;Raymond et al 1994;Parungo et al 1995;Gallo et al 1996;Lyons et al 1996;Travis 1997;O'Brien 1998). • Application of the physical and mathematical underpinnings of meteorology and atmospheric science to determining how the climate system works, how it varies (i.e., climate as a boundary condition [Bryson 1997]), and how it might also be predicted (or climate dynamics [Gates 1979]), particularly as revealed by General Circulation Models (GCMs).…”

Assessing avian diversity and community composition along a successional gradient in traditional Lacandon Maya agroforests

“…The MABR contains most of the remaining Lacandon rain forest, which is classified as a perennial broadleaf rain forest (Hernández‐Ruedas et al, 2014). The region is a biodiversity hotspot containing up to 25% of Mexico's total species diversity (Bobrow‐Strain, 2007; Homer‐Dixon, 1996; O'Brien, 2004). The region's annual rainfall is between 2,300 and 2,600 mm with a dry season from January through April, and the mean temperature is 24.7°C (Servicio Meterológico Nacional, 2010).…”