The Change of North China Climate in Transient Simulations Using the IPCC SRES A2 and B2 Scenarios with a Coupled Atmosphere-Ocean General Circulation Model

This paper applies the newest emission scenarios of the sulfur and greenhouse gases, namely IPCC SRES A2 and B2 scenarios, to investigate the change of the North China climate with an atmosphere-ocean coupled general circulation model. In the last three decades of the 21st century, the global warming enlarges the land-sea thermal contrast, and hence, causes the East Asian summer (winter) monsoon circulation to he strengthened (weakened). The rainfall seasonality strengthens and the summer precipitation increases significantly in North China. It is suggested that the East Asian rainy area would expand northward to North China in the last three decades of the 21st century. In addition, the North China precipitation would increase significantly in September. In July, August, and September, the interannual variability of the precipitation enlarges evidently over North China, implying a risk of flooding in the future.

The predicted effects of climate change on local species distributions around Beijing,China

To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change,this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula platyphylla,Quercus palustris,Platycladus orientalis,plus other mixed broadleaf species—in Beijing using a classification and regression tree niche model under the International Panel on Climate Change’s A2 and B2 emissions scenarios(SRES).The results show that climate change will increase annual average temperatures in the Beijing area by 2.0–4.7℃,and annual precipitation by 4.7–8.5 mm,depending on the emissions scenario used.These changes result in shifts in the range of each of the species.New suitable areas for distributions of B.platyphylla and Q.palustris will decrease in the future.The model points to significant shifts in the distributions of these species,withdrawing from their current ranges and pushing southward towards central Beijing.Most of the ranges decline during the initial 2012–2040 period before shifting southward and ending up larger overall at the end of the 88-year period.The mixed broadleaf forests expand their ranges significantly.The P.orientalis forests,on the other hand,expand their range marginally.The results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 years.Water stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature reserves.There is a potential for the extinction of some species.Therefore,long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.

Prediction Research of Climate Change Trends over North China in the Future 30 Years

A simulation of climate change trends over North China in the past 50 years and future 30 years was performed with the actual greenhouse gas concentration and IPCC SRES B2 scenario concentration by IAP/LASG GOALS 4.0 （Global Ocean-Atmosphere-Land system coupled model）, developed by the State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics （LASG）, Institute of Atmospheric Physics （IAP）, Chinese Academy of Sciences （CAS）. In order to validate the model, the modern climate during 1951-2000 was first simulated by the GOALS model with the actual greenhouse gas concentration, and the simulation results were compared with observed data. The simulation results basically reproduce the lower temperature from the 1960s to mid-1970s and the warming from the 1980s for the globe and Northern Hemisphere, and better the important cold （1950 1976） and warm （1977-2000） periods in the past 50 years over North China. The correlation coefficient is 0.34 between simulations and observations （significant at a more than 0.05 confidence level）. The range of winter temperature departures for North China is between those for the eastern and western China＇s Mainland. Meanwhile, the summer precipitation trend turning around the 1980s is also successfully simulated. The climate change trends in the future 30 years were simulated with the CO2 concentration under IPCC SRES-B2 emission scenario. The results show that, in the future 30 years, winter temperature will keep a warming trend in North China and increase by about 2.5~C relative to climate mean （1960-1990）. Meanwhile, summer precipitation will obviously increase in North China and decrease in South China, displaying a south-deficit-north-excessive pattern of precipitation.