In this blog post, we will look at what climate change is and answer some common questions that arise on this subject which will hopefully become more clearer for you. So, without further ado, let’s dive straight into it.
Are weather and climate the same thing?
The words weather and climate are sometimes used interchangeably. Weather refers to atmospheric conditions such as rainfall, snow, winds, temperature, and clouds that occur for a short period of time from minutes to hours or days. Weather changes in a day or hours and from place to place. For example, you might be wearing shorts and playing outside while at other places, you might be shoveling from a snowstorm. Climate refers to the long-term regional or global patterns such as rainfall, temperature, and humidity over seasons, annually, or decades. Weather can change in just a few hours while climate takes hundreds or even millions of years to change. Climate change refers to change in the earth’s usual weather conditions such as temperature and rainfall in local, regional, and global climates.
What is the difference between climate change and global warming?
The term global warming is used interchangeably with climate change, though these are not the same. Climate change is a broader term that includes the impacts of greenhouse gases and global warming is one of the impacts. Climate change encompasses a wide range of atmospheric variants including extreme weather conditions, natural disasters, and forecast unpredictability.
Is the increase in global temperatures caused by human or natural activity?
Earth’s climate is always changing. There have been times when earth’s temperature was warmer or cooler than it is now and these times last thousands or millions of years. This natural phenomenon leads to evolution for wildlife and species. A lot of people say that global warming is due to natural activities. There are many activities that can cause the climate to change naturally. For example, the distance of the earth from the sun may change or the sun can send more or less energy. A volcanic eruption may also change our climate.
Human activities can also lead to climate change. Scientists agree that human activities produce an excessive amount of greenhouse gases such as methane, carbon dioxide, and nitrous oxides, which are the force behind climate change since the industrial revolution. In the last 60 years, the human-caused carbon pollution has nearly doubled[i], and it is further escalating at faster rates. Human activities such as fossil fuel burning, are a major contributor to the production of greenhouse gas emissions.
As per the climate change scientist, Devyani Kumari of UBC, anthropogenic or, human activities caused climate change to begin during the Industrial revolution.
In the Intergovernmental Panel on Climate Change (IPCC) special report, human-induced warming reached approximately 1°C (likely between 0.8°C and 1.2°C) above pre-industrial levels in 2017, increasing at 0.2°C (likely between 0.1°C and 0.3°C) per decade (high confidence).
How do greenhouse gases cause climate change?
The warmth of the sun is vital for life to exist. A small part of the incoming radiations is absorbed by our atmosphere while the remaining is bounced back. Our earth would have been a frozen rock, without this insulation layer in which carbon dioxide is the most important gas.
The carbon is stored all over the planet in plants, soil, oceans, and even in living organisms. Humans release this stored in the atmosphere through activities such as the burning of fossil fuels and deforestation. We have released a significant amount of carbon dioxide and other greenhouse gases. The greenhouse gases act like a blanket, which causes heat trapping in the atmosphere over the earth. The trapped heat is released slowly which affects things like wind circulation, cloud movement, precipitation, and temperature. There is an increase in carbon dioxide emissions globally, which contributes to global warming. The rising carbon dioxide, methane, or other greenhouse gas levels in the atmosphere causes agitation, heating, and further boiling of our local weather and the global climate system, thereby leading to climate change.
Rob Jackson, a professor at Stanford University in California, said that methane emissions are two and a half times higher now than what they were before the Industrial Revolution. Methane emissions are 28 times more potent than carbon dioxide emissions for global warming. This significant increase in methane emissions is largely due to human activity in agriculture and industry. The list of the world’s top emitters of carbon dioxide is provided below.
How can we be certain climate change is happening?
As compared to weather changes, the effects of climate change are quite gradual. The global temperature rise that we see now is the result of greenhouse gas emissions in the past. However, even a small increase in average global temperature can create catastrophic changes in the world. The rising global warming leading to a continually destabilizing climate shall be a vital sign of the greatest disruptors of normal life. The picture below shows the impacts of climate change on our day-to-day life.
Some of the major evidence of climate change are:
Increase in temperatures:
As per the IPCC report, in many regions, the earth’s global temperature has already surpassed 1.5 degrees Celsius above pre-industrial levels. Also, more than one-fifth of all humans live in regions that have already seen warming greater than 1.5 degrees Celsius in at least one season.
Scientists say that this increase is primarily due to increased carbon dioxide and other human-made emissions.
Shrinking ice sheets:
The ice-sheets in Greenland and Antarctic have decreased notably. As per the data from NASA’s Gravity Recovery and Climate Experiment, Greenland lost an average of 286 billion tons of ice per year between 1993 and 2016[i]. During the same period, Antarctica lost around 127 billion tons of ice per year with the rate of ice mass loss by three times.
Declining Arctic Icesheets:
The Arctic sea ice is declining in extent and thickness over the last few decades. According to the National Oceanic and Atmospheric Administration’s annual Arctic Report Card, the thickest ice in the Arctic has declined by 95 percent over the past three decades of global warming.
We can see the glaciers retreat almost everywhere in the world including the Himalayas, Alps, Africa, and Alaska.
Between 1980 and 2018, glaciers tracked by the World Glacier Monitoring Service have lost ice equivalent to 21.7 meters of liquid water—the equivalent of cutting a 24-meter (79-foot) thick slice off the top of each glacier[i].
Mean sea-level rise:
The global sea level has risen about 8 inches in the last century. This rate has nearly doubled in the last two decades compared to that of the last century. In 2018, the global sea level was 3.2 inches (81 mm) above the 1993 average—the highest annual average in the satellite record (1993-present)[i].
In many locations along the United States coastline, high-tide flooding is now 300% to more than 900% more frequent than it was 50 years ago.
Studies show that the acidity of surface ocean waters has increased by around 30 percent since the Industrial Revolution. The increased amount of carbon dioxide caused by human emissions is being absorbed into the oceans which causes acidification.
As per the IUCN report, in the last three years, coral reefs have suffered mass bleaching as a result of global mean temperature caused by greenhouse gas emissions due to human activities.
The frequency and extent of extreme events such as high temperature, flooding, cyclones, and droughts have increased due to the impacts of climate change.