What are the biggest contributors to climate change?

The science is in: Human activity is warming the planet. As world leaders prepare to gather for a U.N. climate summit in Glasgow, Scotland, to address the “code red for humanity” posed by climate change, Yahoo News explains the leading causes and sources of emissions that lead to global warming.

Video transcript

EVE HARTLEY: If you search on the internet for the causes of climate change, many of the image results will show smoke billowing out of coal plants. Your search engine's top results point to the truth. The burning of coal, natural gas, and oil for heat and electricity is the largest source of greenhouse gas emissions globally. However, there are also many other factors to take into consideration. Let us explain.

If we back it up a little, the planet is warming, in part, because of something called the greenhouse effect. This is when the sun's rays hit the Earth and the majority of that radiation bounces right back out into space. But during that process, a small portion is absorbed by chemicals in our atmosphere. These are called greenhouse gases. Human activities, for instance, the way we heat our homes, fuel our cars, and what food we produce all contribute to more gases such as carbon dioxide, methane, and others, which is a process that drives up the temperature of the planet.

So what is the biggest contributor to climate change? According to data by the EPA, electricity and heat generation accounts for 25% of all global greenhouse gas emissions. Food and land contributes 24%, industry 21%, while transportation contributes to 14%.

So where in the world are these greenhouse gases coming from? Not all continents are equal when it comes to greenhouse gas emissions. Research from the University of Oxford, using measurements from 2017, found Asia is by far the largest emitter, accounting for 53% of global emissions, followed by North America at 18%, Europe at 17%, Africa and South America at 3% to 4% each, and Oceana, which includes Australia and a number of Pacific Islands, at just 1.3% of global emissions.

One thing to note here is that the figures recorded emissions from fossil fuels and cement production only, but it does give us a good idea of where things stand. When you break it up by country and population, the numbers start to look a little different. China, the United States, and India lead the world in carbon emissions. When you account for population, that order changes, and the per capita emissions from the US, China, and India are dwarfed by a number of much smaller nations like Qatar and even Trinidad and Tobago.

Because global warming is a global problem, solutions come from both individuals and countries. More renewable energy sources, dietary shifts, moving to electric transport systems, and the halting of the extraction of fossil fuels are all solutions that could help. We hope that helps you understand how emissions are affecting your world.