Climate change is no longer some far-off problem;
it is happening here,
it is happening now.

Climate is used to express the condition of the atmosphere of a place. The word is quite close to the season. Climate is used for large plots only for a large period while weather is used for small space for relatively small period. 

Climate change is a term used to refer to changes in the Earth’s climates, at local, regional, or global scales. This can also refer to the effects of these changes. In other words, "Climate change is  defined as a significant variation of average weather conditions—like, conditions becoming warmer, wetter, or drier—over several decades or more."It is a long-term trend that separates climate change from natural weather variability. Our knowledge and understanding about climate change and its causes and effects on the world is developing more than ever before. It is now clear within the scientific community that climate change is real. Changes are happening at this rate which is many more than before and human-caused carbon emissions into the atmosphere are contributing to this accelerated rate of global climate change.   
We ourselves are the biggest reason why climate change is happening so fast. The rapid climate change now is caused by humans using oil, gas, wood and coal for their homes, factories and transport. When these fossil fuels  burn, the greenhouse gas releases mostly carbon dioxide(CO2).These gases trap the Sun's heat and raises the temperature of the earth. Reducing emissions of greenhouse gases through better transport, food and energy-use choices results in improved health, particularly through reduced air pollution.  In fact, the average temperature of the planet has increased by 0.8º Celsius (33.4° Fahrenheit) compared to the end of the 19th century.   
The second major source of climate change is deforestation which releases carbon dioxide in atmosphere. It is estimated that harvesting, fires and forest conservation release an average of 8.1 billion metric tons of carbon dioxide per year, accounting for more than 20 percent of all global CO2 emissions.      

Other human activities that generate air pollution include fertilizer use (a primary source of nitrous oxide emissions), livestock production (a major methane emitters), and certain industrial processes that release fluorinated gases. Earth's climate change is also happening due to activities like agriculture and road construction.    

Scientists say that if we want to avoid climate change, then the rise of temperature will not have to be reduced. They say that global warming needs to be maintained at 1.5 F by 2100.If we do not control it now, then by the end of this century the earth may be hotter than 2C.Scientists believe that if nothing is done now, global warming could exceed 4K, which can lead to disastrous heat waves. Millions losing their homes to rising sea levels and irreversible loss of plant and animal species.   

People in vulnerable areas will be the least able to cope without support for preparedness and response in most developing countries. WHO supports countries in building health systems and protect health and helps in tracking national progress from climate change.