Climate Change is a shift in the average conditions of a particular area or location, and we are seeing this all around the world with devastating floods, fires, droughts, hotter bodies of water, sea-level rise, and powerful storms. There seems to be two major schools of thought regarding the sources of Climate Change. The first and probably the most scientifically supported explanation, is human activity. Specifically, this rapid change in climate is the direct result of humans using fossil fuels like oil, gas, and coal for transportation, factories, homes, and other activities. When we burn fossil fuels they release “greenhouse gases.” The second is that Climate Change is a natural phenomenon, and that human activity is hardly responsible, if at all. We have a more detailed discussion regarding this school of thought in our Climate Change Denial section.
Weather and Climate. Temperatures around the world are rising, and the resulting changes in climate are threatening not only nature and ecosystems, but human life all around the planet. But what is climate change? Is it about changes in our weather? Weather is different from Climate. Weather refers to short-term changes in the atmosphere. Weather is a combination of temperature, visibility, wind, precipitation, humidity, and cloudiness –conditions we normally check daily in our different localities. As you already know, weather can change from hour to hour, day to day, month to month, or year to year. We can get the local weather anytime. Climate is different. Climate is the average weather in a particular location over a long period of time – 30 years or more. Climate is an area’s long-term weather pattern(s).Different climate types include tropical, dry, temperate, continental, and polar. The climate is normally hotter closer to the equator because the sun’s light is most directly overhead. In contrast, the North Pole and South Pole are normally colder because light and heat from the sun are least direct at both poles.
What are Greenhouse Gases? Greenhouse gases are gases in the atmosphere that trap heat. The main gases causing this greenhouse effect are carbon dioxide, methane, nitrous oxide, and water vapor, all of which occur naturally. Fluorinated gases which are synthetic (i.e. hydrofluorocarbons), are also greenhouse gases, but do not occur naturally and are manmade. Carbon dioxide (“CO2”) is the most dangerous and prevalent greenhouse gas in Earth’s atmosphere accounting for roughly 75%of global emissions, followed by methane with 16%, and nitrous oxide with 6%.Methane is released from landfills, natural gas and petroleum industries, and agriculture. Believe it or not, methane is produced in the digestive systems of grazing animals like cows. Nitrous oxide is produced from agriculture and livestock, fertilizer, manure, and burning fuel. Although water vapor is earth’s most abundant greenhouse gas, it is not directly emitted by human activity (like CO2), and its effects are not well understood, and therefore is not tracked like the other greenhouse gases.
What is the “greenhouse effect?” How does it work? If you have seen a greenhouse, it usually is a glass building with a glass roof and walls, and it is mostly used to grow plants, flowers, and vegetables. The interesting feature of a green house is that even when it is cold outside, inside the greenhouse it remains warm enough for people to grow plants in winter. This happens because during the day the sunlight shines into the greenhouse through the glass and warms the plants and air inside. But when the sun goes down and it is colder outside, the greenhouse still stays warm enough for the plants inside. So, what’s going on? The greenhouse glass is actually “trapping” the heat of the sun inside the greenhouse. Look at the picture below.
The greenhouse effect on Earth is very similar. Greenhouse gases like CO2 and methane in Earth’s atmosphere trap heat like the glass heat in the greenhouse. If there were no greenhouse gases in Earth’s atmosphere, Earth’s surface would warm during the day from sunlight, and then cool at night as it releases heat back into the air. But WE DO NEED SOMEOF THAT HEAT TO BE TRAPPED BY GREENHOUSE GAS, because if ALL that heat from the sunlight shining through Earth’s atmosphere simply bounced off Earth and disappeared beyond Earth’s atmosphere, Earth would be a freezing, cold planet. So, it is a delicate balance. At night, when Earth’s surface cools, some of the heat released into the air is trapped by greenhouse gases in Earth’s atmosphere and sent back to Earth. This cycle is what makes Earth livable for humans and most other creatures. BUT– too much greenhouse gas traps too much heat which then reflects to Earth. TOO MUCH HEAT, is making Earth TOO HOT which is hastening climate change on Earth.
How are humans impacting the greenhouse effect? Human activities are changing Earth's natural greenhouse effect. Burning fossil fuels like coal and oil puts more carbon dioxide into our atmosphere. NASA has observed increases in the amount of carbon dioxide and other greenhouse gases in our atmosphere. As we have seen, too much of these greenhouse gases can cause Earth's atmosphere to trap more and more heat that warms up the Earth a lot faster than it should.
What reduces the greenhouse effect on Earth? Just like the glass greenhouse, Earth is full of plants and vegetation which help balance the greenhouse effect on Earth. All plants, from giant Redwood and Sequoia trees to tiny phytoplankton in the ocean, take in carbon dioxide and give off oxygen. Our oceans also absorb a lot of excess carbon dioxide in the air. Unfortunately, the increased carbon dioxide that our oceans are absorbing makes the water more acidic and this process is called ocean acidification. Ocean acidification can be harmful, especially to corals. Warmer waters are the main cause of coral bleaching. A sobering fact: Today, Earth is 1.2C warmer than it was in the 19th century, and there is 50% more CO2 in Earth’s atmosphere. Bottom line – we must reduce or limit greenhouse gases in our atmosphere, so Earth doesn’t get much warmer. The warmer Earth gets, the more severe the climate consequences will be.
References:
https://www.bbc.com/news/science-environment-24021772
https://education.nationalgeographic.org/resource/greenhouse-effect
