Introduction

Climate change is one of the biggest challenges our planet faces today. Many natural and human-induced factors contribute to climate change. We are seeing a rapid change in weather conditions such as increased rainfall, extreme heatwaves, rising sea levels, storms, floods, wildfires, melting ice, and loss of wildlife. Climate change is affecting every part of life on the earth. 

If you are among those who are concerned about climate change and confused about the climate change jargon such as mitigation, carbon-neutral, or tipping point, you are not alone.

Here is a quick guide to seven common terms that will help you understand climate change better.

Mitigation:

It refers to using new technologies, renewable energies, or changing consumer behaviour to reduce the flow of heat-trapping greenhouse gases in the atmosphere. Around the world, billions of people depend on traditional fuels such as coal and wood to meet their basic energy needs. Fossil fuels such as coal, oil, and natural gas are used to run vehicles and generate electricity. The burning of fossil fuels produces greenhouse gases such as carbon dioxide, etc. These gases, when released, stay in the atmosphere for a longer period and trap heat. It leads to global warming. We can mitigate climate change by;

• Using solar and wind power rather than coal-fired power plants
• Designing our cities in a way that people have to drive less
• Reconstructing buildings to make them more energy efficient
• Reducing the source of these gases, for example, burning of fossil fuels for heat or transport
• Promoting sustainable use of land and forest
• Making our vehicles and appliances more energy-efficient to use less fuel and electricity.
• Planting more trees and protecting our forests because trees can absorb greenhouse gases present in the atmosphere.

Adaptation:

It involves adjusting in response to actual or expected climate change in an ecological or social system. The warm climate contributes to heatwaves, droughts, longer wildfire seasons, snowstorms, and intense hurricanes. Adaptation involves the actions that reduce the negative effect of climate change and take advantage of new opportunities. It can be reactive (in response to climate change) or anticipatory (before the impact of the climate change). Countries need to develop various adaptation solutions to respond to the impact of climate change. Adaptation solutions include:

• Planting street trees that can reduce stormwater runoff
• Switching to drought-resistance crops
• Creating flood defences
• Redesigning government policies
• Setting up an early warning system for cyclones
• Using environment-friendly paints and cleaning products
• Car-pooling or using public transport
• Making seawalls, dikes, and levees that act as flood barriers and protect infrastructures
• Increasing groundwater storage for drought management
• Installing low-head dams in tidal estuaries to prevent upstream movement of water   

CO2 removal:

Carbon dioxide removal approaches involve climate change by removing carbon dioxide from the atmosphere. Carbon dioxide can be removed from the atmosphere by directly binding CO2 using chemical processes or by increasing the biological sink of CO2. 

Methods to remove CO2 include;

• Trees are a good source to remove CO2 from the atmosphere as photosynthesis removes CO2 naturally.
• Planting cover crops in bare fields increase carbon in the soil.
• Bio-energy with Carbon Capture and Storage (BECCS) involves biomass for energy in the industrial and transportation sector. It captures and stores carbon underground before emission.
• Carbon is scrubbed chemically from the air and stored either underground or long-lived products such as concrete.
• Carbon-mineralisation is a process in which some minerals react with CO2 naturally and convert it into a solid. This process can be enhanced by exposing these minerals to CO2 in the air.

Carbon neutral:

It means adding no net CO2 to the air. According to climate change experts, carbon neutrality by the middle of the 21st century is essential. A balance between the released carbon and carbon absorbed from the atmosphere is called carbon neutrality. Either carbon sink or CO2 removal helps in balancing carbon in the atmosphere.

Natural carbon sinks such as forests, oceans, and soil absorb carbon. However, the stored carbon is released into the atmosphere through changes in land use or forest fire. Thus, it is crucial to reduce carbon emissions to achieve carbon neutrality. The use of renewable energy and other low-carbon technologies helps to reduce carbon emissions and to reach carbon neutrality. Sequestration (removing CO2 from the air and storing it) also helps achieve carbon neutrality.

Tipping point:

This technical term refers to large-scale changes in the climate after crossing some threshold and triggering a new transition at a faster rate. For example, climate change may cause a collapse of the West Antarctic Ice Sheet (WAIC). WAIC can raise the sea level by 3.2 metres. If the global average temperature rises by 2° C, 99% of the sea corals are estimated to be lost. The Greenland ice sheet can raise the global sea levels by 7.2 metres, and its disintegration due to climate change would change the shape of global coastlines. Loss of alpine glaciers, holes in the ozone layer in the Arctic caused by climate change, and decline of Arctic sea ice are other tipping points.  

Unprecedented transition:

According to the Intergovernmental Panel on Climate Change (IPCC-48), currently, we are facing the consequences of 1°C of global warming, such as extreme heat waves, shrinking Arctic sea ice, rising sea levels, and other changes. Warming of 2°C is estimated to worsen global and regional climate impact. So, limiting the average global warming temperature rises to 1.5°C as compared to 2°C would avoid climate change impact. For example, with global warming of 1.5°C, global sea-level rise would be 10cm lower compared to 2°C by the year 2100. Coral reefs that are projected to decline by >99% with 2° C of warming would decline by 70-90% with 1.5°C of global warming. So, every bit of warming would increase the risk for irreversible and long-lasting changes.

Limiting global warming to 1.5°C requires a rapid transition in the land, transports, buildings, energy, and industry. The emission of CO2 caused by humans would need to fall by 45% by 2030 and net-zero around 2050. A balance would be needed between CO2 emission and the removal of CO2.