Recent and future climate change in east asia

Abstract

The signing of the UN Framework Convention on Climate Change in Rio de Janeiro in June 1992 by 160 nations has firmly identified global climate change due to human pollution as a pressing global environmental concern. Among the responsibilities that the nations which ratify the Convention will have are the drawing up of inventories of greenhouse gas sourccs and sinks and the formulation of national strategies to respond to climate change through adaptive and/or preventive measures. One requirement for identifying appropriate response strategies will be the undertaking of regional assessments of climate change and its associated impacts.This paper is concerned with climate change in the East Asian region, both over the last 100 years (using instrumental data) and also for the next 100 years (using results from climate model experiments). The juxtaposing of these two analyses, historical and future, enables a better interpretation of the significance of regional climate change to be made. lnstrumental temperature and precipitation data for the East Asian region are analysed and compared with the observed global-scale trends in these two variables. Although the region has undoubtedly warmed over the last century, understanding the exact causes of the complex seasonal, diurnal, and spatial dimensions of this warming is difficult. We examine the role of increasing urbanization in inducing rising temperatures and suggest that, although substantial, urban warming cannot account for all of the observed temperature change. The paper also illustrates a flexible composite-model approach to regional climate change scenario construction that avoids the need for multiple transient GCM experiments, which can explicitly incorporate the effects of intermodel uncertainty, and is flexible enough to incorporate new scientific findings and results from new GCM experiments. The scenario presented here suggests that by 2050, meon conditions are expected to be warmer than the extremely warm seasonal anomalies that occurred during the most recent decade in East Asia. Precipitation is estimated to rise over most of the region in all seasons, although the uncertainty range attached to this estimate is much wider than for temperature. K E Y WORDS Climate change East Asia Climate scenarios General circulation models Model validation

Exploratory Temperature and Precipitation Reconstructions from the Qinling Mountains, North-Central China

“…Our reconstruction agrees well with the East Asia MAM temperature curve of Hulme et al (1994), with the exceptions of variations during the 1960s and 1980s, when our reconstructed temperatures appear lower than the instrumental record. In addition, our record does not record the century-length trend in instrumental temperature, which culminates in extreme warmth during the 1980s (Hulme et al 1994 [their Figure 3]; Yatagai and Yasunari, 1994 [their Figure 4]).…”

“…Warm springs (March through May; MAM) during the aforementioned periods are noted by instrumental mean temperature records for East Asia, which, prior to 1950, rely heavily on the long records of coastal stations (Hulme et al 1994). Our reconstruction agrees well with the East Asia MAM temperature curve of Hulme et al (1994), with the exceptions of variations during the 1960s and 1980s, when our reconstructed temperatures appear lower than the instrumental record.…”

Severe summer rainfall in China associated with enhanced global warming

“…Over eastern Asia, the modeling of regional scale precipitation sensitivity to global warming also has many uncertainties (Li et al 1994(Li et al , 1995. For example, in earlier GCM experiments presented by Hulme et al (1994), precipitation was estimated to rise over most of eastern Asia in all seasons; however, the uncertainty range attached to this estimate is much wider. It is hard to tell whether the recently observed wetter trend has been induced by the enhanced greenhouse effect.…”

Impacts of global warming on changes in the East Asian monsoon and the related river discharge in a global time-slice experiment

“…However, the EAM change under global warming conditions has hardly been investigated. Wang & Ye (1993) and Nitta & Hu (1996) found from observational data a pronounced warming trend in North China.Using observational data, Hulme et al (1994) concluded that coinciding with warming in the last century, East Asian precipitation increased with a trend of 0.54% decade -1 , which is larger than the global average for land areas (0.25% decade -1 ). Analyzing model simulations, they further suggested that by 2050 the mean temperatures of East Asia will be higher than the warm seasonal anomalies that occurred during the last decade.…”