My Science School

The long-term heating up of the planet due to human activity since the 19th century pre-industrial era is called global warming. One of the main causes driving global warming is the burning of fossil fuels which increases the level of heat-trapping greenhouse gases in the atmosphere. Research has pointed out that human activities have increased the earth's average temperature by about 1 degree Celsius. From the atmosphere to ocean and land, the temperature is rising. The figure is projected to increase with every passing decade. Rising temperatures can impact sea level, thaw glaciers, affect rainfall patterns and lead to extreme events such as hurricanes, flash floods and tomados.

What causes global warming?

 Global warming occurs when carbon dioxide (CO2) and other air pollutants collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally this radiation would escape into space, but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. These heat-trapping pollutants—specifically carbon dioxide, methane, nitrous oxide, water vapor, and synthetic fluorinated gases—are known as greenhouse gases, and their impact is called the greenhouse effect.

Though natural cycles and fluctuations have caused the earth’s climate to change several times over the last 800,000 years, our current era of global warming is directly attributable to human activity—specifically to our burning of fossil fuels such as coal, oil, gasoline, and natural gas, which results in the greenhouse effect. In the United States, the largest source of greenhouse gases is transportation (29 percent), followed closely by electricity production (28 percent) and industrial activity (22 percent).

Curbing dangerous climate change requires very deep cuts in emissions, as well as the use of alternatives to fossil fuels worldwide. The good news is that countries around the globe have formally committed—as part of the 2015 Paris Climate Agreement—to lower their emissions by setting new standards and crafting new policies to meet or even exceed those standards. The not-so-good news is that we’re not working fast enough. To avoid the worst impacts of climate change, scientists tell us that we need to reduce global carbon emissions by as much as 40 percent by 2030. For that to happen, the global community must take immediate, concrete steps: to decarbonize electricity generation by equitably transitioning from fossil fuel–based production to renewable energy sources like wind and solar; to electrify our cars and trucks; and to maximize energy efficiency in our buildings, appliances, and industries.

How is global warming linked to extreme weather?

 Scientists agree that the earth’s rising temperatures are fueling longer and hotter heat waves, more frequent droughts, heavier rainfall, and more powerful hurricanes.

In 2015, for example, scientists concluded that a lengthy drought in California—the state’s worst water shortage in 1,200 years—had been intensified by 15 to 20 percent by global warming. They also said the odds of similar droughts happening in the future had roughly doubled over the past century. And in 2016, the National Academies of Science, Engineering, and Medicine announced that we can now confidently attribute some extreme weather events, like heat waves, droughts, and heavy precipitation, directly to climate change.

The earth’s ocean temperatures are getting warmer, too—which means that tropical storms can pick up more energy. In other words, global warming has the ability to turn a category 3 storm into a more dangerous category 4 storm. In fact, scientists have found that the frequency of North Atlantic hurricanes has increased since the early 1980s, as has the number of storms that reach categories 4 and 5. The 2020 Atlantic hurricane season included a record-breaking 30 tropical storms, 6 major hurricanes, and 13 hurricanes altogether. With increased intensity come increased damage and death. The United States saw an unprecedented 22 weather and climate disasters that caused at least a billion dollars’ worth of damage in 2020, but 2017 was the costliest on record and among the deadliest as well: Taken together, that year's tropical storms (including Hurricanes Harvey, Irma, and Maria) caused nearly $300 billion in damage and led to more than 3,300 fatalities.

The impacts of global warming are being felt everywhere. Extreme heat waves have caused tens of thousands of deaths around the world in recent years. And in an alarming sign of events to come, Antarctica has lost nearly four trillion metric tons of ice since the 1990s. The rate of loss could speed up if we keep burning fossil fuels at our current pace, some experts say, causing sea levels to rise several meters in the next 50 to 150 years and wreaking havoc on coastal communities worldwide.

Credit : NRDC

Picture Credit : Google

A climate pattern describing the unusual warming of surface waters in the easter tropical Pacific Ocean, El Nino corresponds to the warm phase of the larger phenomenon known as the El Nino-Southern Oscillation (ENSO). The pattern that describes the unusual cooling of the region's surface waters, or the cool phase of ENSO, is referred to as La Nina. Ocean temperatures, the speed and strength of ocean currents, health of local fisheries, and the local weather of regions from Australia to South America and beyond are affected by the El Nino, which is not a regular cycle.

The El Nino phenomenon caused muddy rivers to overflow along the entire Peruvian coast in 2017.

El Nino can be understood as a natural phenomenon wherein the ocean temperatures rise especially in parts of the Pacific ocean. It is the nomenclature which is referred to for a periodic development along the coast of Peru. This development is a temporary replacement of the cold current along the coast of Peru.   El Nino is a Spanish word. The term El Nino basically means ‘the child’. This is due to the fact that this current starts to flow around Christmas and hence the name referring to baby Christ.

Another natural phenomenon, similar to El Nino is La Nina, which is also in news these days. The term La Nina literally means ‘ little girl’. It is termed as opposite to the phenomenon of El Nino as it results in the ‘cooling’ of the ocean water in parts of the Pacific ocean.   Both of them also result in changes in atmospheric conditions along with oceanic changes.

El Nino Effects

El Nino results in the rise of sea surface temperatures
It also weakens the trade winds of the affected region
In India, Australia, it can bring about drought conditions. This affects the crop productivity largely. It has been also observed certain times, that EL Nino may not bring drought but cause heavy rainfall. In both the cases, it causes heavy damage.
However, in some other countries it may result in a complete reversal, i.e., excessive rainfall.

 Mitigation Of  Effects:

Keeping a check on the sea surface temperatures.
Maintaining sufficient buffer stocks of food grains and ensuring their smooth supply.
Ensuring relevant support to the farmer community including economic help.
Alternative ways to be promoted such as the practice of sustainable agriculture.

Credit : BYJUS.com

Picture Credit : Google 

The long-term shifts in temperature and weather patterns is referred to as climate change. While these shifts have been natural for the longest period of humanity, human activities have become the main driver of climate change since the 1800s. This is mainly due to the burning of fossil fuels like coal oil and gas, which then produces heat-trapping gases to alter the delicate equilibrium governing the Earth in a negative fashion.

What Causes Climate Change?

There are lots of factors that contribute to Earth’s climate. However, scientists agree that Earth has been getting warmer in the past 50 to 100 years due to human activities.

Certain gases in Earth’s atmosphere block heat from escaping. This is called the greenhouse effect. These gases keep Earth warm like the glass in a greenhouse keeps plants warm.

Human activities — such as burning fuel to power factories, cars and buses — are changing the natural greenhouse. These changes cause the atmosphere to trap more heat than it used to, leading to a warmer Earth.

When human activities create greenhouse gases, Earth warms. This matters because oceans, land, air, plants, animals and energy from the Sun all have an effect on one another. The combined effects of all these things give us our global climate. In other words, Earth’s climate functions like one big, connected system.

Thinking about things as systems means looking for how every part relates to others. NASA’s Earth observing satellites collect information about how our planet’s atmosphere, water and land are changing.

By looking at this information, scientists can observe how Earth’s systems work together. This will help us understand how small changes in one place can contribute to bigger changes in Earth’s global climate.

Credit : Climate kids 

Pictyre Credit : Google