Abstract: This study estimates the relationship between farm level net-revenue and climate variables in India using cross-sectional evidence. Using the observed reactions of farmers, the study seeks to understand how they have adapted to different climatic conditions across India. District level data is used for the analysis. The study also explores the influence of annual weather and crop prices on the climate response function. The estimated climate response function is used to assess the possible impacts of a ‘best-guess’ climate change scenario on Indian agriculture.

Abstract: The growth rate of climate forcing by measured greenhouse gases peaked near 1980 at almost 5 W/m2 per century. This growth rate has since declined to ≈3 W/m2 per century, largely because of cooperative international actions. We argue that trends can be reduced to the level needed for the moderate “alternative” climate scenario (≈2 W/m2 per century for the next 50 years) by means of concerted actions that have other benefits, but the forcing reductions are not automatic “co-benefits” of actions that slow CO2 emissions. Current trends of climate forcings by aerosols remain very uncertain. Nevertheless, practical constraints on changes in emission levels suggest that global warming at a rate +0.15 ± 0.05°C per decade will occur over the next several decades.

Abstract: Impacts of greenhouse effects (2 × CO2) upon climate change over China as simulated by a regional climate model over China (RegCM / China) have been investigated. The model was based on RegCM2 and was nested to a global coupled ocean-atmosphere model (CSIRO R21L9 AOGCM model). Results of the control run (1 × CO2) indicated that simulations of surface air temperature and precipitation in China by RegCM are much better than that by the global coupled model because of a higher resolution. Results of sensitive experiment by RegCM with 2 × CO2 showed that the surface air temperature over China might increase remarkably due to greenhouse effect, especially in winter season and in North China. Precipitation might also increase in most parts of China due to the CO2 doubling.

Abstract: These results from the National Research Programme on Climate Change of the Netherlands offer a synthesis of present knowledge in the fields of: source and sinks of greenhouse gases and aerosols; land-atmosphere interactions; the global energy balance; and radiative forcing and climate variability.

Abstract: Global climate is a result of the complex interactions between the atmosphere, cryosphere (ice), hydrosphere (oceans), lithosphere (land), and biosphere (life), fueled by the nonuniform spatial distribution of incoming solar radiation. We know from climate reconstructions using recorders such as ice cores, ocean and lake sediment cores, tree rings, corals, cave deposits, and ground water that the Earth's climate has seen major changes over its history. An analysis of the temperature variations patched together from all these data reveals that climate change occurs in cycles with characteristic periods, for example 200 million, 100,000, or 4–7 years. For some of these cycles, particular mechanisms have been identified, for example forcing by changes in the Earth's orbital parameters or internal oscillations of the coupled ocean-atmosphere system. However, major uncertainties remain in our understanding of the interplay of the components of the climate system. Paleoclimate reconstructions, in particular from ice cores (1) also have shown that climate can change (e.g., ΔT = 5°C) over extremely short periods of time such as a few years. Over the last century, humans have altered the Earth's surface and the composition of its atmosphere to the extent that these factors measurably affect current climate conditions. There is concern that perhaps during one human generation we will gradually change climate conditions or even trigger a rapid and much more dramatic shift. We might be “poking an angry beast” (2).

Abstract: Climate is constantly changing, and the signals indicating that changes are occurring can be evaluated over a range of temporal and spatial scales. Climate can be viewed as an integration of complex weather conditions averaged over a significant area of the Earth (typically on the order of 100 km2 or more), expressed in terms of both the mean of weather represented by properties such as temperature, radiation, atmospheric pressure, wind, humidity, rainfall and cloudiness (among others) and the distribution, or range of variation, of these properties, usually calculated over a period of 30 years. As the frequency and magnitude of seemingly unremarkable events, such as rainstorms, change, the mean and distribution that characterize a particular climate will start to change. Thus the factors influencing climate, as defined here, range from events occurring over periods measured in hours on up through global processes taking centuries.

Abstract: We introduce climate impact response functions as a means for summarizing and visualizing the responses of climate-sensitive sectors to changes in fundamental drivers of global climate change. In an inverse application, they allow the translation of thresholds for climate change impacts (‘impact guard-rails’) into constraints for climate and atmospheric composition parameters (‘climate windows’). It thus becomes feasible to specify long-term objectives for climate protection with respect to the impacts of climate change instead of crude proxy variables, like the change in global mean temperature. We apply the method to assess impacts on terrestrial ecosystems, using the threat to protected areas as the central impact indicator. Future climate states are characterized by geographically and seasonally explicit climate change patterns for temperature, precipitation and cloud cover, and by their atmospheric CO2 concentration. The patterns are based on the results of coupled general circulation models. We study the sensitivity of the impact indicators and the corresponding climate windows to the spatial coverage of the analysis and to different climate change projections. This enables us to identify the most sensitive biomes and regions, and to determine those factors which significantly influence the results of the impact assessment. Based on the analysis, we conclude that climate impact response functions are a valuable means for the representation of climate change impacts across a wide range of plausible futures. They are particularly useful in integrated assessment models of climate change based on optimizing or inverse approaches where the on-line simulation of climate impacts by sophisticated impact models is infeasible due to their high computational demand.

Abstract: Over the past 2O0 years, human activities have significantly altered the world's atmosphere Despite international efforts to reduce emissions of greenhouse gases, increases in greenhouse gas concentrations will continue and future climate change is inevitable Regional changes in other climatic factors, such as rainfall, will be associated with this warming

Abstract: An analysis of the climatic fluctuations recorded in Lithuania over the 19–20th centuries suggests that, against a background of global warming, trends of climatic elements changeability have been varying with different seasons of the year: winters and springs have warmed up, precipitation in the cold period of the year has increased, whereas summer and autumn temperatures have changed just insignificantly. Thus, the continental character of the climate could be treated to have fallen into a general decline, which is observed throughout Europe and not only in Lithuania. As projected by forecast climate models, by the middle of the 21st century the Lithuanian climate will have warmed up 1.5–1.7°C. Yet, climate change tendencies could be altered by reduced emissions of greenhouse gases and the related worldwide control, as well as by the distribution of temperature anomalies in the Arctic Region and the adjacent latitudes, and by the associated changes in the ocean and atmospheric circulation.

Abstract: Publisher Summary This chapter discusses the global climate prediction and the uncertainties of such predictions. The chapter uses the expression climate prediction only in the context of the ability to simulate or predict the overall statistics of climate. An intransitive climate would then be a priori unpredictable, because infinitesimal changes in the initial data or in the forcing may change the climate in ways similar to the chaotic processes that limit the length of useful weather forecasts. There are several indications of the nonuniqueness of the earth's climate, one of them related to the thermohaline circulation of the ocean. The additional fact that climate is the integral of weather over long periods of time, the weather itself being unpredictable, mean that the predictability of climate is a fundamental issue. The uncertainties of global climate prediction are a broad subject therefore the chapter is restricted to a time scale of a few hundred years and thereby concentrate on the time from early industrialization to the middle of the next century.

Abstract: Publisher Summary This chapter summarizes oceanic processes and features that are important in defining the ocean's role in climate It also introduces climate phenomena in which the ocean is known to play a significant role The ocean's vital roles in the climate system results from its great capacity to store and transport heat, water and radiatively active gases around the globe and exchange these with the atmosphere The full three-dimensional ocean circulation needs to be adequately represented in global atmosphere-ocean general circulation models if realistic projections of climate on decadal and longer time scales are to be completed, including projections of abrupt climate change This level of ocean complexity is also required for realistic projections of greenhouse gas concentrations in the atmosphere to be made and for the simulation of the timing and regional impact of anthropogenic climate change The ocean not only plays a fundamental role in moderating and modifying the atmospheric climate, but it is also the environment within which marine organisms live, and it strongly influences the ocean boundaries Thus, it can be said to have a climate itself that has a direct and important impact on society's use of the oceans, their living resources and their coastal boundaries

Abstract: Long-term variability in the North Atlantic Oscillation (NAO) and the Atlantic thermohaline ocean circulation (THC) are both shaping the European climate on time scales of decades and longer. Possible linear and non-linear changes in the characteristics of these natural climate modes due to global warming are an important source of uncertainty in long-term regional projections of future climate changes.

Abstract: Increasing the concentration of greenhouse gases in the atmosphere will strengthen the natural greenhouse effect, which could lead to global climate warming and more other changes. China is a largely agricultural country with a large size of population and the relative shortages of farming lands and water resources, thus increasing the importance of climate warming for national economy development. Therefore. Chinese government and scientists have paid great attention to the impact-assessment of climate warming on national economy in China, especially during the past 10 years. This presentation will briefly describe some major issues of climate warming impact research on national vegetation, agriculture, forest, water resources, energy use and regional sea level for China, etc.As a result, all climate change scenarios derived by GCMs suggest a substantial change in thecharacteristic natural vegetation types. It is also shown that comparing with the distributionsimulated under thenormal time period 1951-1980 as the present climate, by 2050 large changesin cropping systems would occur almost everywhere in China. Climate warming would lead toincrease cropping diversification and multiplication. Unfortunately, the possible net balancebetween precipitation and evapotranspiration would be negativeand it would lead to reduce thegrain production in China significantly due to enhanced moisture stress in soil. The most evidentinfluence of climate warming on water resources would happen in Huanghe-Huaihe-Haihe Basin andthe water supply-demand deficit would be substantially enhanced in this area. And also, a warmerclimate for China will alter the energy requirement for domestic heating and cooling, that is,reduce energy use for heating in northern China and increase energy consumption for cooling insouthern China.

Abstract: Overview A strong consensus among climate scientists has emerged on key aspects of global climate change: humans have unquestionably altered the composition of the atmosphere in significant ways, there has been an increase in global average temperature of 0.4 – 0.8°C (0.7 – 1.5°F) in the past 100 years, and this increase in temperature is probably caused in part by the atmospheric changes wrought by humans. In the future, the accumulation of greenhouse gases is expected to lead to further warming of 1.4 – 5.8°C (2.5 – 10.4°F) by 2100, with moderate (at the low end) to dramatic (at the high end) consequences for humans and global ecosystems. The uncertainty in this wide range of estimates stems about equally from uncertainty about natural feedbacks in the climate system and from estimates of future socioeconomic change. Climate models are the best tool available for understanding future climate change. CIG has extracted output for the PNW region from eight global climate model simulations, which taken together project a regional warming of 1.7 – 3.5°C (3.1 – 6.3°F) by the 2040s, with modest increases in winter precipitation. Even with wetter winters, however, the region will likely face reduced summer flows as rising temperatures reduce winter snowpack depth and distribution. Climate models simulate large-scale temperature much better than other quantities like precipitation; consequently, confidence in the projections of future temperature is higher than for other climate variables. Climate change is expected to continue beyond the 2040s and probably even beyond 2100.

Abstract: The first part of this review paper summarizes the changes in Hungarian temperature and precipitation series during this century. Then, some possible hydrological, agricultural and ecological consequences of a future climate change are outlined, obtained after using empirical downscaling techniques developed for estimation of local effects of a global climate change. Finally, local temperature and precipitation changes corresponding to the doubling of the concentration of atmospheric greenhouse gases obtained with a stochastic downscaling method are presented. Climate of Hungary has become warmer and dryer during this century. The global climate change expected under increasing concentration of atmospheric greenhouse gases further contributes to this tendency.

Abstract: In recent decades, the role of greenhouse gases on climate change since human industrialization has been emphasized in floods of papers and books Here, we review the causes of climate change during the 20th century, and some new evidences for decoupling of atmospheric greenhouse gases and climate from ice cores and geological records, and then point out some important issues needed to be further studied, such as the age difference between ice and young air it encloses, and the correlation between the Sun and the Earth climate

Abstract: Greenhouse gases such as CO2、CH4、N2O、 HFCs、PFCs、SF6are present in the atmosphere in greater amounts than at any ti me in at least 220,000 years.and it is main cause that heating the globe.Global climate warming is having devastating impacts on plants,animals and human society.there is a critical need for decreasing emission of greenhouse gaese by scientific and powerful measure.

Abstract: There is continued scientific and public debate about the possibility of future climatic changes that may result from human activity such as the burning of fossil fuels since the 18th century. Within this context, the article provides a brief review of the ocean's role within the global climate system. It illustrates how the ocean regulates the Earth's climate and how it asserts control over the climate system. One key feature of the present state of the ocean climate is a global thermohaline circulation, which allows for an exchange of heat and greenhouse gases in a conveyor belt type fashion throughout the ocean interior. Continuous mixing of surface water into the deep ocean caused by complex ocean and atmosphere processes may have already led to a global ocean warming. The detection of a human induced greenhouse effect against the background of natural climate variability is a difficult task. Daily, seasonal, or decadal changes in temperature, for example, are much larger than the anticipated human induced temperature increase of only several tenths of a degree. This climate variability is discussed by using several prominent examples. In the last section of this article, observations of climate variability in the South Pacific Ocean are described. It is here, where a fingerprint of global ocean warming may have already been found in recently collected data. When compared to historical data records from the 1960s, these new data indicate a warming of the subsurface ocean. Today's policy and decision makers wait for more pronounced signals of an enhanced greenhouse effect to arrive and scientists continue to search for further convincing evidence. However, one benefit of global climate and ocean research is the discovery and study of a suite of previously unknown climate system phenomena during the last two decades.

Abstract: The risk of climate change with negative impacts on water resources and water management has stimulated many hydrological impact studies in recent decades. General Circulation Models (GCM) are often used to provide regional climate scenarios. Unfortunately, regional results between different GCMs differ significantly. In this paper, the uncertainty of hydrological impact assessments which results from climate scenarios derived by different GCMs is specified for a river basin in Germany. By a probabilistic analysis with 25 000 climate scenarios it is shown that the hydrological changes depend mostly on the specific GCM which is used to generate a regional scenario. Another important source of uncertainty is the unknown sensitivity of the world climate to increases of the atmospheric concentration of greenhouse gases. Taking into consideration our incomplete knowledge about the regional effects of climate change we cannot expect confident predictions of future hydrological conditions. Water managers should accept the restrictions of all prognoses and be able to consider a wide range of uncertainties in their planning.

Abstract: Climate change is again in the news. First the failure of the COP6 1 meeting to agree on terms for the Kyoto Protocol and now the apparent rejection of the protocol by President Bush leaves the future of climate policy uncertain. To move forward it is important understand the drivers of climate change in order to inform discussions of where mitigation efforts need to be focused. This paper will present a quantitative overview of the physical drivers of past and future climate changes. The paper will first address attribution of past climate changes, then the radiatively important substances that will drive future climate change, and, finally, the mitigation of climate change in the context of the recent Hansen et al. “alternative scenario”. 2 This discussion will be framed in terms of radiative forcing. Radiative forcing is the energy imbalance caused by a change in the climate system and is defined as the change in radiative flux at the top of the troposphere after allowing for stratospheric adjustment. 3 Since radiative forcing refers to a change, this quantity must always be given relative to some reference date or concentration level. Radiative forcing is measured in units of Watts per square meter. A doubling of carbon dioxide concentrations, for example, will cause an imbalance of approximately 3.7 W/m 2 . 4 The total forcing from all anthropogenic greenhouse gases, as compared to pre-industrial times, is presently (~ year 2000) about 2.7 W/m 2 , with an offset of perhaps half this amount from aerosol cooling (see below). 5 The radiative forcing caused by carbon dioxide is known to within about 1%. Uncertainties for the other important greenhouse gases are 5-10%, with higher uncertainties for some halocarbons. 4,6