Climate change. Global warming. Paris Agreement. Greenhouse gases. Carbon neutral. Fossil fuels. Renewable energy. Energy efficiency. Climate justice. Have you been hearing these words pop up more often? What does it all mean? Let’s break down some of the key terms.
Climate vs. weather: Weather is the short-term conditions at a specific time and can change rapidly. For example, it is 26 degrees and cloudy as I write this today in Columbus, Ohio. Meteorologists are predicting it will be 21 degrees and snowing on February 16th and that on February 23rd the temperature will go up to 38 degrees with rain. Climate is the long-term daily average of that weather. In Columbus, Ohio it is hot and humid in the summer with high temperatures around 85 degrees in July and cold in the winter with low temperatures around 20 degrees in January.
Climate change: 97% of scientists agree that the climate is changing. The earth’s average surface temperature has risen 2 degrees Fahrenheit (or 1 degree Celsius) since 1880 with the 7 most recent years being the warmest recorded. Along with rising temperatures, there have also been melting ice sheets, decreasing snow cover, rising sea levels, and more extreme weather events like hurricanes and wildfires. The impact of climate change varies by region with some areas having more extreme temperature changes than others and with some regions getting wetter while others get drier.
Global warming: While you may sometimes hear the terms global warming and climate change used interchangeably, global warming is actually just one component of climate change. Global warming refers to the rising temperatures while climate change includes all aspects of the changing climate like temperature, precipitation, and wind.
Greenhouse effect: The greenhouse effect is the natural warming of the earth. Natural greenhouse gases found in the atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Sunlight passes through the atmosphere and then the greenhouse gases capture some of the heat from the sun to keep the planet a comfortable temperature. That’s a good thing because it keeps the earth warm enough to support life for plants, animals, and humans. However, increased concentrations of these gases have led to more heat being captured and rising temperatures.
Carbon dioxide: Carbon dioxide is an important greenhouse gas. However, atmospheric concentrations of carbon dioxide have been increasing at unprecedented rates. The concentration of carbon dioxide in the atmosphere was measured at 415 parts per million (ppm) in December 2020. Scientists have used ice core samples to track carbon dioxide levels over the last 800,000 years. While levels have fluctuated in the past, they have never before increased above 300 ppm and never increased at the fast rate we have seen in recent years. Reducing carbon dioxide levels in the atmosphere will be key to controlling climate change.
Paris Agreement: The Paris Agreement is an international treaty to combat climate change with a goal to limit global warming to less than 2 degrees Celsius, and ambitiously to below 1.5 degrees Celsius. The treaty was adopted by 196 countries in Paris in 2015. Nations each commit to actions they will take to reduce greenhouse gas emissions and adapt to the effects of climate change. In order to achieve the goal of 1.5 degrees Celsius, the world needs to target being carbon neutral by 2050.
Carbon neutral / Net zero: Carbon neutral, also known as net zero carbon, is the term used when carbon emissions are offset by carbon savings so the net effect is no increase in carbon dioxide in the atmosphere. Carbon neutrality can be reached by increasing energy efficiency, transitioning to energy sources that have lower carbon emissions, and carbon sequestration. Many governments and companies are making net zero pledges.
Carbon negative / Climate positive: Some organizations are taking the net zero pledge even further, making commitments to remove more carbon dioxide from the atmosphere than they add to it. This can be referred to as being climate positive or carbon negative.
Fossil fuels: Fossil fuels – primarily coal, petroleum, and natural gas – have long been the main source of energy around the world. Fossil fuels continue to provide 80% of energy consumed in the U.S. Fossil fuels have been key in fueling our economy but, unfortunately, they have also been a main contributor to climate change. In 2018, the burning of fossil fuels contributed 93% of all human-caused carbon dioxide emissions. Lower carbon alternatives and carbon capture technologies are being explored to reduce future emissions but consideration needs to be given to the people and places being impacted by such transitions.
Renewable energy: Renewable energy sources – primarily solar, wind, hydropower, geothermal, and biomass – are produced from earth’s resources that are naturally replenished. Renewable energy provided 11% of energy consumed in the U.S. in 2019, 3 times more than was consumed in 2000. Renewable energy is desirable because there are fewer emissions and it is becoming more affordable. But other impacts need to be considered as well including consistency of generation and availability, land and water use, and materials used to produce the equipment such as solar panels and wind turbines.
Energy efficiency: Energy efficiency is simply using less energy to perform the same task. This is achieved through new technologies, updated designs, and changed human behavior. Examples of improved energy efficiency can be found in LED light bulbs, home insulation, and fuel-efficient cars. A study by the ACEEE shows that the U.S. can achieve 50% of the needed greenhouse gas reductions needed by 2050 by implementing existing energy efficiency technology.
Carbon sequestration: Carbon sequestration is the capture and long-term storage of carbon dioxide. Luckily, we already have a technology that is very effective at removing carbon dioxide from the atmosphere – plants. Land use adjustments such as reforestation, addition of green spaces, and improved agricultural practices can help reduce carbon dioxide concentrations in the atmosphere. Carbon capture and storage technology can also be used to capture carbon dioxide from industrial emissions, transport it, and store it deep underground.
Carbon credits / Carbon offsets: Organizations can purchase carbon credits, also known as carbon offsets, to help meet their carbon neutral commitments by paying someone else to reduce or remove emissions. Examples include forestry, renewable energy, and agricultural projects. Carbon credits are a key tool to offset the unavoidable emissions after other reduction efforts have been made. However, organizations should not continue business as usual and use carbon credits as the only emissions reduction tactic.
Climate justice: Climate change is not just an environmental issue. It is also a social and economic issue. Climate change does not impact all people equally. Often, low-income communities, people of color, women, and older populations are more susceptible to the impacts of climate change like severe heat, drought, poor air quality, and flooding. Climate change solutions must protect the most vulnerable.
There is no one size fits all solution to climate change. It will take a combination of efforts including improved energy efficiency, lower carbon energy production, and carbon capture. And it is going to take all of us – governments, businesses, and individuals – to take action to meet climate change targets.
We are small compared to the world around us, but we can have a BiG impact!