Research On The Characteristics And Effects Of Climate Extremes On Multi Spatial Temporal Scales In The Mongolian Plateau

Climate change has been attracting extensive attention worldwide due to its significant and irreversible impacts on the human living environments including hydrometeorological disasters, freshwater availability, land use and land change, urbanization, food production, disease outbreaks, and many other aspects. It has caused huge socio-economic losses, and is the utmost obstacle to the sustainable development of human society. Therefore, addressing the above problems is an urgent and necessary issue to explore the impacts of climate change on different aspects of the human living environment, as an important basis to adopt effective adaptive measures and actions for mitigation of climate change impacts.

Wetlands and grassland are important components of natural ecosystems, which have rich values in maintaining ecological balance, regional economy and human development. Wetlands can provide freshwater resources and food sources for human beings, purify the water environment and mitigate climate change. The grassland ecosystem has such ecological functions as windbreak, sand fixation, soil preservation, climate regulation, air purification, water conservation and so on, which are closely related to human survival and well-being. In recent years, climate change and human activities have caused a profound impact on the structure and function of wetland and grassland ecosystems, and the problems of decline in size and function have attracted extensive attention from researchers globally. However, there are still many uncertainties about the variety of wetland and grassland ecosystem composition, structure and dynamics, as well as how they respond and adapt to climate change and human activities.

This report focuses on the risks of climate change to development in Sub-Saharan Africa, South East Asia and South Asia. Building on the 2012 report, Turn Down the Heat: Why a 4°C Warmer World Must be Avoided, this new scientific analysis examines the likely impacts of present day, 2°C and 4°C warming on agricultural production, water resources, and coastal vulnerability. It finds many significant climate and development impacts are already being felt in some regions, and that as warming increases from present day (0.8°C) to 2°C and 4°C, multiple threats of increasing extreme heat waves, sea-level rise, more severe storms, droughts and floods are expected to have further severe negative implications for the poorest and most vulnerable. The report finds that agricultural yields will be affected across the three regions, with repercussions for food security, economic growth, and poverty reduction. In addition, urban areas have been identified as new clusters of vulnerability with urban dwellers, particularly the urban poor, facing significant vulnerability to climate change. In Sub-Saharan Africa, under 3°C global warming, savannas are projected to decrease from their current levels to approximately one-seventh of total land area and threaten pastoral livelihoods. Under 4°C warming, total hyper-arid and arid areas are projected to expand by 10 percent. In South East Asia, under 2°C warming, heat extremes that are virtually absent today would cover nearly 60-70 percent of total land area in northern-hemisphere summer, adversely impacting ecosystems. Under 4°C warming, rural populations would face mounting pressures from sea-level rise, increased tropical cyclone intensity, storm surges, saltwater intrusions, and loss of marine ecosystem services. In South Asia, the potential sudden onset of disturbances to the monsoon system and rising peak temperatures would put water and food resources at severe risk. Well before 2°C warming occurs, substantial reductions in the frequency of low snow years is projected to cause substantial reductions in dry season flow, threatening agriculture. Many of the worst climate impacts could still be avoided by holding warming below 2°C, but the window for action is closing rapidly. Urgent action is also needed to build resilience to a rapidly warming world that will pose significant risks to agriculture, water resources, coastal infrastructure, and human health.