Climate change is the greatest global threat to coral reef ecosystems. Scientific evidence now clearly indicates that the Earth’s atmosphere and ocean are warming, and that these changes are primarily due to greenhouse gases derived from human activities.
According to the Intergovernmental Panel on Climate Change, so far the oceans have taken up 90% of the excess heat generated by human-caused global warming. Even if emissions are aggressively curtailed, the oceans will continue heating at an accelerating rate for decades. What’s more, the oceans are acidifying. They’ve soaked up an estimated 20–30% of human carbon emissions; as carbon dioxide dissolves into these waters, their pH plummets.
Warming and acidification are stressors for corals (and for many other marine organisms). Heat causes coral to lose its algae and bleach. At the same time, increasing acidity makes it difficult for individual corals, typically millimeters in size, to build the calcium carbonate deposits that form large reef structures. If the pH is low enough and the corals unhealthy enough, reefs can even start to dissolve, making them vulnerable to shattering during storms.
Unhealthy reefs threaten not only the organisms that inhabit them but also the livelihoods of the people who depend on them. Reefs are the backbone of near-shore ecosystems around the world, providing a home for thousands of species of fish as well as mollusks, crustaceans, sea turtles, and countless other creatures. Without their associated reefs, nearby fisheries are at risk of collapse. The world’s reefs are valued in the tens to hundreds of billions of dollars annually. Each year, for instance, the Great Barrier Reef contributes about A$5.6 billion (US$3.84 billion) to Australia’s economy.
Scientists around the world are looking for all kinds of ways to protect and maybe even revive corals. One option is to create more marine protected areas—essentially national parks in the ocean. Scientists say creating marine refuges, where fishing, mining, and recreating are off limits, make the reefs healthier, and so more resilient.
NASA describes climate change as a long term change in the average weather patterns preexisting in local, regional and global climate. Most of the changes observed in Earth’s climate since the early 20th century are primarily driven by human activities, particularly fossil fuel burning which releases greenhouse gasses like methane, nitrogen dioxide and most importantly, carbon dioxide (CO2). These gasses are heat trapping in nature and are raising the Earth’s average surface temperature. The temperature increased caused by man-made activities is referred to as global warming.
Global warming is causing extreme weather events like floods, cyclones, draughts, forest fires, heat waves, and hurricanes and melting polar ice caps of the planet. India being a tropical country faces floods every year. We also have huge coastline spanning 7,500-odd km and runs past nine states which are very vulnerable to flooding. The rapid melting of polar ice caps because of Global warming has accelerated the rise of sea levels as observed by study conducted by an IPCC panel. This is going to impact people living near the coastal areas and in islands. Mumbai, one of the largest cities in the world, with a population of 20 million is projected to be completely submerged by rising sea levels. Glaciers are also melting in the Himalayas, which is projected to increase flow rates in the Ganges and Brahmaputra Rivers. In 2013, heavy rain followed by a glacial lake outburst caused devastating floods in the state of Uttarakhand. The floods 4,000 people, destroyed and caused damages of 3.8 billion dollars.
Monsoon in 2019 witnessed 560 extreme rainfall events, a 74% jump from 324 events recorded in the year 2018. The heavy rainfall caused floods that led to a death toll of 1685 lives, spread across 14 states of the country, with Maharashtra accounting for the maximum deaths. According to Home Ministry officials heavy rains and floods fully damaged 1.09 lakh houses, partially damaged 2.05 lakh houses and destroyed 14.14 lakh hectares of crops. Responding to floods in different areas at the same time as happened last year strains emergency response efforts. NDRF, Army and the Air Force were deployed to rescue people across six states in northern and western India. An estimated 1.2 million people were living in government relief camps.
According to IPCC panel, the frequency of freak weather events like floods would drastically reduce if the rise in temperature was limited to 1.5 degree Celsius, however it is highly unlikely that we are able to achieve that target. In a study conducted by IIT Gandhinagar, it was found that short bursts of heavy rainfall, lasting only hours, are likely to increase by 20 percent if the global mean temperature rises above 1.5 degree Celsius. Such extreme events will be responsible for most cases of urban flooding.
Carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, or product, expressed as carbon dioxide equivalent. Greenhouse gases, including the carbon-containing gases carbon dioxide and methane, can be emitted through the burning of fossil fuels, land clearance and the production and consumption of food, manufactured goods, materials, wood, roads, buildings, transportation and other services. Here are some ways to reduce your carbon footprint:
The choice of diet is a major influence on a person’s carbon footprint. Animal sources of protein like red meat, rice (typically produced in high methane-emitting paddies), foods transported long-distance or via fuel-inefficient transport (e.g., highly perishable produce flown long-distance) and heavily processed and packaged foods are among the major contributors to a high carbon diet. Scientists at the University of Chicago have estimated that the average American diet – which derives 28% of its calories from animal foods – is responsible for approximately one and a half more tonnes of greenhouse gasses.
Another option for reducing the carbon footprint of humans is to use less air conditioning and heating in the home. By adding insulation to the walls and attic of one’s home, and installing weather stripping, or caulking around doors and windows one can lower their heating costs more than 25 percent. Similarly, one can very inexpensively upgrade the “insulation” (clothing) worn by residents of the home. For example, it’s estimated that wearing a base layer of long underwear with top and bottom, made from a lightweight, super-insulating fabric like microfleece, can conserve as much body heat as a full set of clothing, allowing a person to remain warm with the thermostat lowered by over 5 °C. These measures all help because they reduce the amount of energy needed to heat and cool the house.
There are many simple changes that can be made to the everyday lifestyle of a person that would reduce their GHG footprint. Reducing energy consumption within a household can include lowering one’s dependence on air conditioning and heating, using CFL light bulbs, choosing ENERGY STAR appliances, recycling, using cold water to wash clothes, and avoiding a dryer. Another adjustment would be to use a motor vehicle that is fuel-efficient as well as reducing reliance on motor vehicles. Motor vehicles produce many GHGs, thus an adjustment to one’s usage will greatly affect a GHG footprint.