Unit 1 

Global Warming and Climate Change 

Climate change refers to the long-term changes in temperature, precipitation, wind patterns, and other measures of climate that occur over several decades or longer. The primary cause of climate change is the burning of fossil fuels such as coal, oil, and natural gas, which releases large amounts of carbon dioxide and other greenhouse gases into the atmosphere. 

These gases trap heat from the sun, causing the Earth's temperature to rise. This warming is causing a number of changes to the Earth's climate, including rising sea levels, more extreme weather events, and changes in the distribution of plants and animals. Scientists are using a variety of tools, including computer models and satellite data, to study and understand these changes, and to predict future impacts.

Natural climatic variability Global Warming 

Climate is naturally variable, and has changed throughout Earth's history due to factors such as volcanic eruptions, changes in the Earth's orbit, and variations in solar radiation. However, the current warming trend is different from past natural variability in that it is occurring at an unprecedented rate and is primarily caused by human activities, specifically the burning of fossil fuels.

Global warming refers to the long-term warming of the planet, primarily caused by the burning of fossil fuels, which releases large amounts of carbon dioxide and other greenhouse gases into the atmosphere. These gases trap heat from the sun, causing the Earth's temperature to rise. The Intergovernmental Panel on Climate Change (IPCC) has reported that it is extremely likely that human activities, particularly the burning of fossil fuels, are the main cause of the warming observed since the mid-20th century.

Natural variability still occurs, but the warming caused by human activities is superimposed on top of it and is expected to continue at an unprecedented rate if emissions of greenhouse gases continue to increase.

Natural and Enhanced Greenhouse effect 

The greenhouse effect is a natural process that warms the Earth's surface. It occurs when gases in the Earth's atmosphere, such as carbon dioxide, water vapor, methane, and nitrous oxide, trap heat from the sun, preventing it from escaping into space. This trapped heat warms the atmosphere and the surface of the Earth, making it livable for humans and other organisms.

The natural greenhouse effect is necessary for life on Earth, as it maintains a temperature range that allows liquid water to exist, making it possible for organisms to survive. However, human activities, such as burning fossil fuels, deforestation, and agriculture, have led to an increase in the concentrations of greenhouse gases in the atmosphere, enhancing the greenhouse effect.

This enhancement is referred to as the enhanced greenhouse effect. This is causing the Earth's temperature to rise at an unprecedented rate and is resulting in a number of changes to the Earth's climate, including rising sea levels, more extreme weather events, and changes in the distribution of plants and animals.

Greenhouse Gases & Carbon Emissions  

Greenhouse gases are gases in the Earth's atmosphere that trap heat from the sun, preventing it from escaping into space. These gases include water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3). These gases are responsible for the natural greenhouse effect, which maintains a temperature range that allows liquid water to exist on Earth and thus makes it possible for life to survive.

Carbon emissions refer to the release of carbon-containing gases, primarily carbon dioxide, into the atmosphere. Carbon emissions come from  variety of sources, including the burning of fossil fuels (such as coal, oil, and natural gas), deforestation, and agriculture. The burning of fossil fuels is the largest source of carbon emissions, accounting for about 78% of total greenhouse gas emissions.

Carbon emissions have been rising rapidly since the Industrial Revolution and continue to do so, primarily as a result of increased use of fossil fuels. This increase in emissions is contributing to the enhanced greenhouse effect and is causing the Earth's temperature to rise at an unprecedented rate. Reducing carbon emissions is essential to slow down the rate of climate change and to mitigate its impacts.