Climate change is one of the complex problems facing mankind today. The overriding complexity of the problem is attributed to its deeper global ramifications on a vast range of issues impacting the very survival of life on Earth. Understanding such a complex issue with vast and varied dimensions and implications, assumes greater significance for all stakeholders, especially for our policy makers. There are varieties of perceptions regarding the exact size and consequences of climate change. Yet, it is no secret that risks emanating from climate change are indeed profound, which call for urgent mitigation. There is now strong evidence that climate change is a reality.

Today, it has been scientifically established that significant global warming is occurring. Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. There is no denying the fact that the problem exists and it is assuming alarming proportions, each passing day. Therefore, there is an imperative need to take urgent and strong measures in the interest of calibrating an appropriate response to meet the emerging challenges of climate change.

Climate change is not an isolated issue. It has several aspects and inter-linkages namely, science and technology, economy and trade, diplomacy and politics - that makes it not just another issue in this complicated world of proliferating issues, but the mother of all issues. Climate change, however, is different from other problems facing humanity and it compels us to think differently at many levels. It obliges us to think about what it means to live as part of an ecologically interdependent human community.

In the face of many diversities that characterize human society, climate change provides a potent reminder of one thing that we share in common - the planet Earth. All nations and all people share the same atmosphere. And, we only have one. Addressing the climate chaos by all the countries both individually and collectively, will be critical to the human well-being and prosperity of the present as well as the future generation.

What do we mean by climate change?

Climate change is the long alternative of temperature and normal weather pattern in a place. This could refer to a particular location or the planet as a whole. It is currently occurring throughout the world as a result of global warming. Or we can say that It is a periodic modification of earth’s climate brought about as a result of changes in the atmosphere as well as interaction between the atmosphere and various other geological, biological, chemical and geographical factors within the earth system.

The most common cause of climate change is global warming which is occurred by the greenhouse effect, a natural process by which the atmosphere retains some of the sun’s heat, allowing the earth to maintain the necessary conditions to host life. Without the greenhouse effect. The average temperature of the planet would be 18º C.

Today, humankinds activities are altering the worlds climate. We are increasing the atmospheric concentration of energy trapping gases, thereby amplifying the natural green house effect that makes the earth habitable. These green house gases comprises, principally, carbon dioxide (mostly by fossil fuel), with the heat wrapping gasses such as methane (from animal husbandry, irrigation agriculture, oil extraction), nitrous oxide, and by human made halocarbons.

“there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities” it was stated in the assessment report of Un’s intergovernmental panel on climate change(IPCC) in 2001.

During the 20th century the average surface temperature of the world increased by approx. 0.6*C, and approx. 2/3 of that warming has occurred since 1975. The global scale of climate change differ fundamentally from the many other familiar environmental concern that refers to the localized toxicological or microbiological hazards. Indeed, it signifies that, today, we are altering the earth’s biophysical and ecological system at the planetary scale-as is also evented by the stratospheric ozone depletion, acceleration biodiversity losses, stresses on terrestrial and marine food-production system. European population were all effected by the nature’s great climatic cycle. The IPCC in 2001 estimated that the global average temperature will rise by several degrees centigrade during this century.

Types Of Climate Change Assessments

• Climate change impact assessments:- it is identified and qualified the expected impacts of climate change. These syntheses the current scientific knowledge of the expected effects if climate change on a focus area, such as a resource, economic sector, landscape, or region, for decades to centuries into the future.
  
• Vulnerability assessments: it goes beyond the impact to determine the system’s sensitivity and ability to adapt to climate change, and may be used in place of or in addition to its impact. It is a function of explore, sensitively and adaptive capacity.

1. Sensitivity: it involves environmental thresholds, dependences on other species, interaction with other species, disturbance specialized habit of particular organisms, and other environmental stressors.
   
2. Exposure:it is made up of primary factor (i.e. temperatures, precipitations), secondary factor (i.e. hydrology, sea level rise, vegetation changes), and non- climate stressors (i.e. development, invasive species)
   
3. Adaptive capacity: it include plasticity, dispersal abilities, evolutionary potential, and landscape permeability.

• Natural resources assessments: generally describes the current condition of specific natural resources, and assess factors that are affecting the resources, wish the goal of providing timely, relevant and accessible information for decision makers and policy makers.

Causes of climate change

Earths temperature depends upon the balance between the energy entering and leaving the planets system. When the incoming energy from the sun is absorbed by the earth surface, earth warm. When suns energy is reflected back to the space, earth voids warming when absorbed energy is released back into space, earth gets cool. Many factors both nature and human, can cause changes in earths energy balance, including:

• Variations in the suns energy. Reaching earth
• Changes in the reflectivity of earths atmosphere and surface.

Chances in the greenhouse effect which effects the amount of heat restraint by earths atmosphere.

These factor has caused earths climate to change many times. Mostly earth climate gets effected by the greenhouse effect which causes atmosphere to retain its heat. When sunlight reaches to the earth surface, it can be either be reflected back into the space or absorbed by earth. Once absorbed, the planet releases some of the energy back into the atmosphere as heat also called infrared radiation.

Greenhouse Effect

Greenhouse gases like water vapor , carbon dioxide, and methane absorbs energy, slowing or preventing the loss of heat to space. In this way GHGs act like a blanket, making earth warmer than it would otherwise be. This process is commonly known as “greenhouse effect”.

Recent Role Of Greenhouses Gases in The Atmosphere

Since the industrial revolution began around 1750, human activities have contributed substantially to climate change by adding CO2 and other heat trapping gasses to the atmosphere. These greenhouses gases emissions have increased the greenhouse effect and causes earth surfaces temperature to rise. The primary human activities affecting the amount and rate of climate change is greenhouse gas emission from burning of fossil fuel.

The main gases of the greenhouse:

The most important GHGs directly emitted by humans including carbon dioxide, methane , nitro oxide, and several others like : water vapor, troposphere ozone O3, chlorofluorocarbon (CFCs). Black carbon(BC), sulfates, organic carbon, warming and cooling aerosols these forces effect the change in climate of the earth and causes several diseases to the human life.

Effects Caused By The Climate Change To Human Life

In this wide world , today , there is an apparent increase in many infectious diseases, including some newly circulating ones like(HIV/AIDS, hantavirus, hepatitis C, SARS, etc.). this reflects the combined impacts of rapid demographic, environmental, social, technology and other changes in our ways-of-living climate change will also effect infectious disease occurrence.
In the late 19th century, roman aristocrats retreated to hill resorts each summary to avoid malaria. South Asian learned early that, in higher summer, strongly curried foods were less likely to cause diarrhea. Infectious agents vary gently in size, type and mode of transmission.

There are viruses, bacteria, protozoa and multicellular parasites. Those microbes that cause “anthrophonic” have adapted, via evolution, to the human species as their primary, usually exclusive, host. in contrast, the animals are the natural reservoir for those infections agents that cause “zoonoses” they are directly transmitted anthroponoses such as HIV/AIDS, measles and zoonoses such as rabies. They are also indirectly transmitted, vector-borne, amthroponoses such as malaria, dengue fever, yellow fever. And zoonoses such as bubonic plague and Lyme disease.

Vector-Borne And Water-Borne Diseases

Important determinants of vector borne disease transmission include: (i) Vector survival and reproduction (ii) The vectors biting rate (iii) The pathogens incubation rate within the vector organism. Vectors, pathogens and hosts each survival and reproduced within the range of optimal climatic conditions: temperature and precipitation are the most important, while sea level elevation, wind, and daylight duration are also important.

Human exposure to water borne infections occurs by contact with contaminated drinking water, recreational water, or food. This may results from human actions, such as improper disposal of sewage wastes, or due to weather events. Rainfall can influence the transport and dissemination of infectious agents, while temperature effects their growth and survival.

How Law Supports The Prevention of Climate

The government of India introduces some Laws related to environment which suppose to prevent the climate. As the ENVIRONMENT PROTECTION ACT,1986 authorizes the central government to protect and improve environmental quality, control and reduce pollution from all sources, and prohibit or restrict the setting and operate of any industrial facility on environmental grounds. Environmental law not only aim to protect the environment from harm, but they also determine who can use natural resources and on what terms.

Laws may regulate population, the use of natural resources, forest protection, mineral harvesting and animal and fish populations. Some other law are passed by the government to protect the environment such as THE NATIONAL ENVIRONMENT POLICY ACT (NEPE) passed in 1970 alone with the environmental quality improvement act and the NATIONAL ENVIRONMENTAL EDUCATION ACT. The main objective of these laws was to protect the environment against public and private harm.

Recommendation
Climate related exposures: IPCC’s 3rd assessment report project that as we continue to change atmospheric composition, global average surface temperature will rise up to 1.4 to 5.8ºC in this century. along with changes with precipitation and other climate changing variables.

Reaching consensus on the science :- the science of the climate has achieved increasing consenus among scientists. There is increasing evidence that human health will be affected in many and diverse ways. Knowledge is still limited in many areas, for example on the contribution of short terms climate variability to disease incidents; on development of early warming systems for predicting diseases outbreaks and extreme weather events ; and on understanding how recurring extreme events may weaken adaptive capacity.

Challenges to the scientists: it poses some changes, including the complexity of casual process, the unavoidable uncertainties, and temporal displacement of anticipated impacts into the future. Some important research topics include identifying the first effect of the climate change on human health will be apparent; improving estimate of climate change impacts.

Extreme climate events : the IPCCs report projected changes in extreme climate events that include more hot days and heat waves; more intense precipitation events; increased risk of drought; increase in winds and tropical cyclones (over some areas), intensified droughts and floods with EI Nino events; and increased variability in the Asian summer monsoon.

Infectious diseases: the diseases epically those which are transmitted by insect vectors or water are sensitive to climatic conditions. Incident data is need to provide a baseline for epidemiological studies. The lack of precise knowledge of current diseases incidence rates makes It difficult to comment about whether incident is changing as the result of climate change.

The burden of diseases: the stock of empirical evidence relating climatic trends to altered health outcomes remains spare. This estimating the range timing and magnitude of likely future health impacts of global environment changes. Even initial attempts has been made, within the frame work of the WHO (world health organization) global burden of diseases 2000 project.
Stratospheric ozone depletion, climate change and health: this is essentially a different process from climate change. However, greenhouse warming does effected by many of the chemical and physical processes involved in the depletion of stratospheric ozone.

Monitoring climate change impacts on human health: climate change is likely to affect disease that are also influenced by other factors. Monitoring to assess climate change impacts on health there for, requires data-gathering coupled with analytical method able to quantify the climate attributable portion of such diseases. Monitoring and surveillance system in many countries currently cannot provide useful data on climate sensitive disease. Less developed countries should strengthen existing system in order to meet current needs.

Adapting of climate change : As we know that climate change is already underway and hence we need some adaption policies to complement mitigation policies. Efficient implementation of adaptation strategies can significantly reduce adverse health impacts of climate change.

Suggestions
Precisely at a time when India is confronted with development imperatives, we will also be severely impacted by climate change. With close economic ties to natural resources and climate-sensitive sectors, India may face a major threat, and require serious adaptive capacity to combat climate change. With 27.5 per cent of the population still below the poverty line reducing vulnerability to the impacts of climate change is essential. In response to the predicted changes in public health due to climate change, our policymakers need to work to strengthen the health care systems along with water and wastewater systems. Adaptation will require diverse strategies like inter-sectoral coordination which could include physical modification to the built environment and improved housing and building standards. In order to address some of the predicted changes as well as those are taking place in India in an effective manner, more emphasis is required on the following policies:

• Strengthening health systems and service delivery mechanisms
• Provision of drinking water and sanitation facility to all
• Provision of funding for low income communities with poor sheltering and high exposure/risk to heat and cold wave

Conclusion
The article shows that linkages between climate change and human health are complex and multi-layered and predictions of the future health impacts of climate change are still uncertain. Over India, the annual mean temperature has increased in the past hundred years. Projection of the future climate change scenario shows catastrophic events will exhibit an increase in frequency and intensity resulting in enormous impact on human life in terms of death toll and disease epidemic Climate change is happening and emissions are bound to increase due to growing economy of India.

Therefore, addressing both mitigation and adaptation is important. Even the developed nations are struggling to cope up with the challenges posed by the changing climate; India needs to put more efforts to counter the same. Considering the increasing trend of impact of climate change on human health, adoption of mitigation measures like strengthening health systems and service delivery mechanisms through early Therefore, climate change occurs when changes in earth’s climate system results in new weather patterns that remains in place for an extended period of time. This length of time cab be as short as a few decades to as long as millions of year.

Direct effect of environmental circumstances may ease the diffusion of vector borne and water borne diseases. Economics would play a major role in combating the potential threat. Countries with good GDP would be able to introduce the best available tools of intervention and can fill up the lacunae in health system.

Seeing the cumulating trend of impact of climate change on human health, implementation of alleviation measures like consolidation health systems and service delivery mechanizing through early delivery. Thus for the prevention of the climate change government of India has taken initiatives to protect the environment before the worst come. By enacting the certain laws, principals and some acts to guide the human for the prevention of the environment.