Greenhouse Effect Problem

Before there were humans, the world changed only slowly. The climate warmed and cooled, new plants and animals developed and became extinct (绝灭的) in their turn, and sea level rose and fell over periods of thousands, if not millions of years. But during the last two thousand years great changes have taken place. Forests have disap-

CHANGES OF PRECIPITATION IN CHINA DUE TO THE ENHANCED GREENHOUSE EFFECT

We mainly discuss changes of precipitation in China due to growinggreenhouse gases using GCM1 model assuming the IPCC 'Business-as-Usual'Scenario. An increasing greenhouse effect will lead to precipitation increasesmostly in north of 30°N for winter, and strongly increases alap a slant belt fromNortheast China to Bay of Bangal for summer in China. The mp of increasingprecipitation are about 7.9, -0.7 and 13.6 percent for winter, and 6.4, 12.9 and 8.4percent for summer m China, Changjinang and Huanghe river valleys, respectively.The model results are also shown to imply that an increasing greenhouse effectenhances chanas of intense storms and shown for winter and summer in China.

Influences of greenhouse effect on agricultural production in China

An obvious warming in China induced by doubled carbon, dioxide as simulated by the climatic models have been found. It is also noticed that there might be drying or wetting in some parts of China induced by doubled CO2 as simulated by the general circulation models(GCMs). Agricultural productivity mainly depends on the temperature, rainfall and soil moisture in China. The changes of agricultural productivity in the different parts of China induced by doubled CO2 have been estimated in this paper. It is shown that the greenhouse effect might cause increasing production in some parts of China and decreasing production in other parts of China.

A New Perspective of the Physical Processes Associated with the Clear-Sky Greenhouse Effect over High Latitudes

The physical processes associated with the clear-sky greenhouse effect in the presence of water vapor are examined by including surface emissivity in the greenhouse effect formulation, and by introducing a new way to partition physical processes of the greenhouse effect. In this new framework, it is found that the clear-sky greenhouse effect is governed by three physical processes associated with (1) the temperature contrast between the surface and the atmosphere, (2) the interaction between the surface emissivity and the temperature contrast, and (3) the surface emissivity. The importance of the three physical processes is assessed by computing their vertical and spectral variations far the subarctic winter and summer standard atmosphere using the radiation model MODTRAN3 (Moderate Resolution Transmittance code Version 3). The results show that the process associated with the temperature contrast between the surface and the atmosphere dominates over the other two processes in magnitude. The magnitude of this process has substantial variations in the spectral region of 1250 to 1880 cm-1 and in the far infrared region. Due to the low-level temperature inversion over the subarctic winter, there exists a negative contribution to the greenhouse trapping. The seasonal variations are, however, dominated by the processes associated with the interaction between the surface emissivity and the temperature contrast as well as the surface emissivity itself. The magnitudes of these two physical processes contributing to the greenhouse trapping over the subarctic winter are about 7 to 10 times of those over the subarctic summer, whereas the magnitude of the processes associated with the temperature contrast in the subarctic summer is only about 2 times of that in the subarctic winter.

Sensitivity experiments and assessment of climatic changes in China induced by greenhouse effect

Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in China .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2-5℃ in summer in China as simulated by the GCMs induced by doubling CO2 have been found. There are getting drier or wetter regions in China due to doubled CO2 as simulated by most of models. Comparing the simulated results with the observed data in China, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.

The Greenhouse Effect

Over the past two years, the food culture of the small town of Agarfa in south Ethiopia has seen some tasty changes. Tomatoes, previously unaffordable to all but the very wealthy, have become a common sight on the plates of local people. The secret lies in the introduction of greenhouse tomato growing technology.

CLIMATE CHANGE DUE TO GREENHOUSE EFFECTS IN CHINA AS SIMULATED BY A REGIONAL CLIMATE MODEL-PART Ⅱ:CLIMATE CHANGE

Impacts of greenhouse effects (2×CO_2) on climate change over China as simulated by a regional climate model have been investigated.The model was based on RegCM2 and is nested in one-way mode within a global coupled atmosphere-ocean model (CSIRO R21L9 AOGCM).Two multi-year simulations,the control run with normal CO_2 concentration and sensitivity run with doubled CO_2 concentration are conducted. As Part II of the publications,with a brief analysis of the 2×CO_2 experiment by CSIRO R21Lg,results of the 2×CO_2 simulation by RegCM2 are analyzed in detail. Results of the RegCM show a remarkably warming over China with an increment ranging from 2.2℃ in southern China to 2.8℃ in northern due to greenhouse effect.The regional averaged annual temperature increase is 2.5℃.The warming is greater in winter and spring.Daily maximum and minimum temperatures increase also over China which lead to much more hot spell days in summer and less cold spell days in winter. Precipitation increases in all seasons of the year,with the greatest found in summer.Annual mean precipitation increases significantly in western China,parts of the area in south of the Yangtze River and northern part of the Northeast.while a decrease in the area from southern part of the Northeast to North China is simulated.The regional averaged annual increase of precipitation is 12%.More heavy rain events are found noticeably in southern China.The simulated tropical storms affecting and landing over China tend to increase.Analysis on the simulation of circulation pattern showed that the 500 hPa height in East Asia might rise significantly.

The influence of urban three-dimensional structure and building greenhouse effect on local radiation flux

Accurate measurements of the three-dimensional structure characteristics of urban buildings and their greenhouse effect are important for evaluating the impact of urbanization on the radiation energy budget and research on the urban heat island(UHI)effect.The decrease in evapotranspiration or the increase in sensible heat caused by urbanization is considered to be the main cause of the UHI effect,but little is known about the influence of the main factor“net radiant flux”of the urban surface heat balance.In this study,experimental observation and quantitative model simulation were used to find that with the increase of building surface area after urbanization,the direct solar radiation flux and net radiation flux on building surface areas changed significantly.In order to accurately quantify the relationship between the positive and negative effects,this study puts forward the equivalent calculation principle of“aggregation element”,which is composed of a building’s sunny face and its shadow face,and the algorithm of the contribution of the area to thermal effect.This research clarifies the greenhouse effect of a building with walls of glass windows.Research shows that when the difference between absorption rates of a concrete wall and grass is−0.21,the cooling effect is shown.In the case of concrete walls with glass windows,the difference between absorption rates of a building wall and grass is−0.11,which is also a cooling effect.The greenhouse effect value of a building with glass windows reduces the cooling effect value to 56%of the effect of a building with concrete walls.The simulation of changes in net radiant flux and flux density shows that the greenhouse effect of a 5-story building with windows yields 15.5%less cooling effect than one with concrete walls,and a 30-story building with windows reduces the cooling effect by 23.0%.The simulation results confirmed that the difference in the equivalent absorption rate of the aggregation element is the“director”of cooling and heating effects,and the area of the aggregation element is the“amplifier”of cooling and heating effects.At the same time,the simulation results prove the greenhouse effect of glass windows,which significantly reduces the cold effect of concrete wall buildings.The model reveals the real contribution of optimized urban design to mitigating UHI and building a comfortable environment where there is no atmospheric circulation.

A DIAGNOSTIC STUDY OF FEEDBACK MECHANISM IN GREENHOUSE EFFECTS SIMULATED BY NCAR CCM1

This paper describes a diagnostic study of the feedback mechanism in greenhouse effects of increased CO_2 and oth- er trace gases(CH_4,N_2O and CFCs),simulated by general circulation model.The study is based on two sensitivity exper- iments for doubled CO_2 and the inclusion of other trace gases,respectively,using version one of the community climate model(CCM1)developed at the National Centre for Atmospheric Research.A one-dimensional(1-D)and a two-dimensional(2-D)radiative-convective models are used to diagnose the feedback effect.It shows that the feedback factors in global and annual mean conditions are in the sequence of surface albedo,water vapor amount,water vapor distribution,cloud height,critical lapse rate and cloud cover,while in zonal and annual mean conditions in the tropical region the above sequence does not change except the two water vapor terms being the largest feedback compo- nents.Among the feedback components,the total water vapor feedback is the largest(about 50%).The diagnosis also gives a very small feedback of either the cloud cover or the lapse rate,which is substantially different from the 1-D feedback analysis by Hansen et al.(1984).The small lapse rate feedback is considered to be partly caused by the convective adjustment scheme adopted by CCM1 model. The feedback effect for doubled CO_2 is very different from that of the addition of other trace gases because of their different vertical distributions of radiative forcing although the non-feedback responses of surface air temperature for both cases are almost the same.For instance,the larger forcing at surface by the addition of other trace gases can cause stronger surface albedo feedback than by doubled CO_2.Besides,because of the negative forcing of doubled CO_2 in the stratosphere,cloud height feedback is more intense.The larger surface forcing in the case of other trace gases can also in- fluence atmospheric water vapor amount as well as the water vapor distribution,which will in turn have stronger feedback effects.All these indicate that it is incorrect to use“effective CO_2”to replace other trace gases in the general circulation model.

THE ROLE PLAYED BY THE STRATOSPHERE IN GREENHOUSE EFFECT

Two one-dimensional radiative-convective models with the same scheme and the different ranges that one is from surface to stratopause and the other is from surface to tropopause,have been developed to study the role played by the stratosphere in greenhouse effect.It is shown that the addition of stratospheric response may lead to an increase of 7—50 percent in radiative forcing at the tropopause,and an increase of 20—60 percent in surface temperature when the con- centration of the same gas in the two models increases at the same time;and when the same change in radiative forcing at the tropopause due to the same agent in the two models occurs,the addition of stratospheric response may lead to an in- crease of 5—20 percent in surface temperature;and allowing for the stratospheric adjustment means that the tempera- ture responses to the same flux change due to different causes are in far disagreement.

ELEMENTARY VIEW OF GREENHOUSE EFFECT OF THE ATMOSPHERES OF VARIOUS PLANETS

The global mean temperatures of the atmosphere and the surface of various planets of the solar system are deter- mined by taking the system as in radiative equilibrium,with the atmosphere taken as transparent to solar radiation but with an albedo α,and composed of N layers each of which absorbs all infrared radiation that falls on it,and a top layer of partial absorptivity a,while the surface is taken as black.It is found that,for the earth's atmosphere with α=0.33, N=0,a=0.83,it gives the current observed mean surface temperature T_s=15℃ and the effective mean radiative temper- ature of the atmosphere T_a=242.6K.On the other hand;the atmosphere of Venus is characterized by α=0.70 and N=70,which yields a surface temperature of about 700K. It is also found that surface evaporation and absorption of solar radiation by the atmosphere tend to lower the sur- face temperature.

A Quasi-Linear Relationship between Planetary Outgoing Longwave Radiation and Surface Temperature in a Radiative-Convective-Transportive Climate Model of a Gray Atmosphere

In this study,we put forward a radiative-convective-transportive energy balance model of a gray atmosphere to examine individual roles of the greenhouse effect of water vapor,vertical convection,and atmospheric poleward energy transport as well as their combined effects for a quasi-linear relationship between the outgoing longwave radiation(OLR)and surface temperature(T_(S)).The greenhouse effect of water vapor enhances the meridional gradient of surface temperature,thereby directly contributing to a quasi-linear OLR-T_(S) relationship.The atmospheric poleward energy transport decreases the meridional gradient of surface temperature.As a result of the poleward energy transport,tropical(high-latitude)atmosphere-surface columns emit less(more)OLR than the solar energy input at their respective locations,causing a substantial reduction of the meridional gradient of the OLR.The combined effect of reducing the meridional gradients of both OLR and surface temperature by the poleward energy transport also contributes to the quasi-linear OLR-T_(S) relationship.Vertical convective energy transport reduces the meridional gradient of surface temperature without affecting the meridional gradient of OLR,thereby suppressing part of the reduction to the increasing rate of OLR with surface temperature by the greenhouse effect of water vapor and poleward energy transport.Because of the nature of the energy balance in the climate system,such a quasi-linear relationship is also a good approximation for the relationship between the annual-mean net downward solar energy flux at the top of the atmosphere and surface temperature.

Decoupling CO2 from Climate Change

This study determines if there is a correlation between rising carbon dioxide levels and global warming. Historical data were reviewed from three different time periods spanning 500 million years. It showed that the curves and trends were too dissimilar to establish a connection. Observations from CO2/temp ratios showed that the CO2 and the temperature moved in opposite directions 42% of the time. Many ratios displayed zero or near zero values, reflecting a lack of response. As much as 87% of the ratios revealed negative or near zero values, which strongly negate a correlation. The infrared spectra showed the Greenhouse Gases had an exceptionally low absorption band between 11.67 μm to 9.1 μm, which is a zone called the infrared atmospheric window. Most of the Greenhouse Gases absorb little infrared inside that zone. And that zone is where the Earth’s surface emits almost all infrared radiation. Even with minimal absorbance, water vapor captures the most infrared radiation. It absorbs 84 times more than CO2, 407 thousand times more than methane, 452 thousand times more than ozone and 2.3 million times more than nitrous oxide. The Intergovernmental Panel on Climate Change (IPCC) and the United States EPA excluded water vapor because it was not associated with man-made activities. They reported that water vapor and clouds were simply feedback mechanisms from CO2. Clouds reflect radiation from the sun. The Northern Hemisphere is 2.7°F warmer than the Southern Hemisphere because of clouds. The world cloud cover has gone down 4.1% from 1982 to 2018. Calculations show that this could be responsible for 2.4°F of the 2.7°F. The research shows that most of the recent increase in temperature (89.9%) is because of fewer clouds.

Possible effect of climate changes on the coastal zone of the Yangtze River Delta

A coastal historical evolution of the Yangtze River Delta was discussed in this paper on the basis of the historical data of the coastal zone and an estimation was made for the future change of the coast The emphasis was put on the future climate change that will have influence on the sea wall, coastal navigation and freshwater resources in the Delta It was also pointed out that the global warming and precipitation increase in the Yangtze River Valley may exert more impact on the zone In addition, some measures describing how to adapt to the climate change and reduce its impact were put forward

Numerical Investigation of the Temperature and Flow Fields in a Solar Chimney Power Plant

In this work,a parametric two-dimensional computational fluid dynamics(CFD)analysis of a solar chimney power plant(a prototype located in Manzanares,Spain)is presented to illustrate the effects of the solar radiation mode in the collector on the plant performances.The simulations rely on a mathematical model that includes solar radiation within the collector;energy storage;air flow and heat transfer,and a turbine.It is based on the Navier-Stokes equation for turbulent flow formulated according to the standard k-εmodel.Moreover,the Boussinesq approach is used to account for the fluid density variations.Different solar radiation modes in the collector are compared and discussed.The obtained results are also compared with available experimental results.It is shown that the radiation model is essential to avoid overestimation of the energy absorbed by the plant and that results based on a two-dimensional model can resemble closely those produced by three-dimensional models.

Improving environmental sustainability of intensive care units: A mini-review

The carbon footprint of healthcare is significantly impacted by intensive care units,which has implications for climate change and planetary health.Considering this,it is crucial to implement widespread efforts to promote environmental sustainability in these units.A literature search for publications relevant to environmental sustainability of intensive care units was done using PubMed.This mini-review seeks to equip intensive care unit practitioners and managers with the knowledge necessary to measure and mitigate the carbon cost of healthcare for critically ill patients.It will also provide an overview of the current progress in this field and its future direction.

Qualitative Considerations on the Influence of the Gases Water Vapor and Carbon Dioxide on the Global Environmental Temperature from the Point of View of Textbook Knowledge

The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional energy input or prolongation of the interaction time solar radiation—Earth matter. The contribution of H2O(g) and CO2 to the protection of the earth against excessive warming is experimentally and by basic laws of nature secured. For a greenhouse effect, a part of the earth radiation must be radiated back to the earth and then into space. If one understands the earth radiation as radiation of a black body with the average global environmental temperature, from all vibrations normal modes of the gases H2O(g) and CO2 only the bending mode of CO2 with 4% of the solar constant can contribute beside the rotational modes of the water to the greenhouse effect. The contributions of the normal modes of H2O(g) and CO2 to the heat capacity of the atmosphere are negligible. Therefore, in agreement with studies by K. Ångström, CO2 contributes only to the stabilization of the global environmental temperature. Whether the use of renewable energies can actually at least mitigate the increase of the environmental temperature is by no means certain but must be examined for each individual case. With certainty, this goal can only be achieved by reducing the energy consumption of mankind.

The Influence of Heat Source IR Radiation on Black-Body Heating/Cooling with Increased CO2 Concentration

This study deal with interactions between thermal and radiative energy flow in experimental situations of varying complexity. Of special interest is how IR energy, re-emitted from CO2 gas, behaves in an earth/atmosphere simulated setup. Such an experiment was performed by Hermann Harde and Michael Schnell where they show that IR radiation emitted from CO2 can warm a small black-body metal plate. In a control experiment, we verified this result. However, in their experiment, the amount of IR radiation from the heating element was strongly attenuated. In a modified experiment, where IR emission from the heating source is present, no heating but a slight cooling of a black object is found when air is replaced by CO2. The modified experimental situation is also more like the earth/atmosphere situation. The presence of IR radiation from a heated surface (like when the sun heats the earth’s surface) strongly attenuates the heating ability of increasing backscatter from increased amount of CO2 in the atmosphere. This result has consequences for the climate change models used by IPCC.

Coupled Model Simulations of Climate Changes in the 20th Century and Beyond

Several scenario experiments of the IPCC 4th Assessment Report （AR4） are performed by version g1.0 of a Flexible coupled Ocean-Atmosphere-Land System Model （FGOALS） developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences （IAP/CAS）, including the ＂Climate of the 20th century experiment＂, ＂CO2 1% increase per year to doubling experiment＂ and two separate IPCC greenhouse gases emission scenarios AIB and B1 experiments. To distinguish between the different impacts of natural variations and human activities on the climate change, three-member ensemble runs are performed for each scenario experiment. The coupled model simulations show： （1） from 1900 to 2000, the global mean temper- ature increases about 0.5℃ and the major increase occurs during the later half of the 20th century, which is in consistent with the observations that highlights the coupled model＇s ability to reproduce the climate changes since the industrial revolution; （2） the global mean surface air temperature increases about 1.6℃ in the CO2 doubling experiment and 1.5℃ and 2.4℃ in the A1B and B1 scenarios, respectively. The global warming is indicated by not only the changes of the surface temperature and precipitation but also the temperature increase in the deep ocean. The thermal expansion of the sea water would induce the rise of the global mean sea level. Both the control run and the 20th century climate change run are carried out again with version g1.1 of FGOALS, in which the cold biases in the high latitudes were removed. They are then compared with those from version g1.0 of FGOALS in order to distinguish the effect of the model biases on the simulation of global warming.

Methane and Nitrous Oxide Emissions from Rice-Duck and Rice-Fish Complex Ecosystems and the Evaluation of Their Economic Significance

Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and their economic value from these two ecosystems can provide theoretical and practical basis for further development and utilization of these classical agricultural techniques. CH4 and N2O emissions from RD and RF ecological systems were measured in situ by using static chambers technique. Using global warming potentials （GWPs）, we assessed the greenhouse effect of CH4 and N2O and their economic value. Results showed that the peaks of CH4 emission fluxes from RD and RF appeared at full tillering stage and at heading stage, and the average emission fluxes were significantly （P〈 0.05） lower than that from CK. N2O fluxes remained low when the field is flooded and high after draining the water. Compared with CK, the total amount of N2O emissions was significantly （P〈0.05） higher and slightly lower than those from RD and RF, respectively. In 2006 and 2007, the total greenhouse effect of CH4 and N20 from RD and RF were 4 728.3 and 4 611 kg CO2 ha^-1, 4 545 and 4 754.3 kg CO2 ha^-1, respectively. The costs of greenhouse effect were 970.89 and 946.81 RMB yuan ha^-1, and 933.25 and 976.23 RMB yuan ha^-1, respectively, which were significant lower than those from CK （5 997.6 and 5 391.5 RMB yuan ha^-1）. Except for the environment cost of CH4 and N2O, the economic benefits from RD and RF were 2 210.64 and 4 881.92 RMB yuan ha^-1; 3 798.37 and 5 310.64 RMB yuan ha^-1, respectively, higher than those from CK. Therefore, RD and RF complex ecological planting and breeding models can effectively decrease and control CH4 and N2O emissions, and they are two of the effective strategies to reduce greenhouse gases from rice paddy fields and contribute in alleviating global warming. Thus, their adoption is important to the environment together with their economy benefits.