The Effects of GHGs, Aerosols, and Deforestation on the Temperature and Precipitation Patterns of the Mediterranean Climate Region during the 21st Century

Abstract

AbstractClimate change can be caused by various anthropogenic or natural factors that influence atmospheric changes. The direct link between human activity and the environment is represented by the interaction mechanisms between anthropogenic factors such as urbanization, deforestation, hydrological changes, greenhouse gases and aerosols. These interaction mechanisms are assessed by the current state of knowledge in the climate change field. One of these mechanisms is related to greenhouse gases (GHGs), which increase surface level heating and lowers atmospheric temperature in the long term by increasing atmospheric GHG concentration. This heating reduces air density parcel and increases total evaporation to transfer excess heat from surface (latent heat) to atmosphere. Another mechanism is related to anthropogenic aerosols, which have direct and indirect effects on climate change with variable direct radiative forcing depending on the nature, density and composition of the aerosol particles. Anthropogenic sulphate is the main element that influences atmospheric conditions through its direct and indirect effects, which delay global warming by increasing the albedo and the lifetime of clouds formed by water droplets. A third mechanism is related to deforestation, which affects the environment according to the results of climate models based on deforestation scenarios. Deforestation alters the heat exchange between the oceans (relatively warm) and the atmosphere (relatively cold), generating a sensible heat flux (warming) that influences neighbouring regions. Deforestation also lowers surface temperature by changing coniferous vegetation to tundra and desert, causing a cooling of up to -4°C in North America and − 6°C in Siberia. In Europe, deforestation scenarios show a decrease in surface temperature of -2°C to -3°C in spring and − 1°C in summer in northern mid-latitudes, mainly due to the delayed melting of spring snow.