What are Greenhouse Gases?
Greenhouse gases (GHGs) are gases in the atmosphere that trap solar heat.
The major heat-trapping gases that we have here on Earth are water vapor, carbon dioxide (CO2), methane, nitrous oxides, and chlorofluorocarbons (CFCs). In normal concentrations, these greenhouses gases (GHGs) can actually help life on Earth, since most species are adapted to the current global average surface temperature of 59°F.
GHGs warm the planet through their interaction with the light that the sun shines on Earth. Incoming sunlight is primarily visible and ultraviolet light, and the rays that are not reflected are absorbed by the Earth. This absorbed light warms the Earth the way that sunlight warms your skin. GHGs do not simply absorb incoming UV or visible light though; they play their role in the next step of the process.
The Earth then emits some of that warmth as infrared light, and this light either goes out to space or is bounced back to Earth by GHGs in the atmosphere. The more GHGs, the more light is bounced back and reabsorbed by the Earth. This difference in incoming and outgoing radiation is what creates the “greenhouse effect”, which keeps the Earth’s average surface temperature at 59°F (15°C) instead of 0°F (or -18°C).
How Are Humans Impacting Greenhouse Gas Concentrations?
As mentioned before, changes in atmospheric greenhouse gas concentrations can change the temperature on Earth. Over the past 800,000 years, atmospheric CO2 concentrations have fluctuated slightly but stayed below 300ppm. However, since the beginning of the Industrial Revolution in about 1850, humans have been artificially increasing the emissions of CO2 and other GHGs beyond natural levels.
These increased GHG emissions largely stem from activities such a fossil fuel-powered electricity, heating, transportation, and agricultural practices. Fossil fuel combustion emits a lot of CO2, livestock production is responsible for emitting large quantities of methane, synthetic fertilizer usage is a large cause of nitrous oxide emissions, and air-conditioners, refrigerators, and aerosol cans emitted many CFCs before the Montreal Protocol banned the use of CFCs across most of the globe in 1987. Humans have luckily not had as marked of an impact on the concentration of water vapor.
Here at UMass Lowell, electricity, heating, and transportation each account for roughly a third of our GHG emissions each. For more information, the EPA has a comprehensive webpage on global greenhouse gas emission sources.
What Is Climate Change?
These increased GHG emissions are increasing atmospheric GHG concentrations, which in turn increases the average global temperature. However, this change in temperature can also result in a vast array of climatic changes, or changes in long-term weather patterns.
Climate refers to longer-scale patterns of weather, usually averaged over a period of 30 years. Weather can describe the amount of rain that falls in a single storm, whereas climate refers to average yearly rainfall for a certain area. Such changes of the climate include but are not limited to: sea level rise, intensified temperature fluctuations (both cold snaps and heat waves), and increased droughts and flooding.
Climate change impacts vary depending on location. Some areas are more prone to flooding, others are more prone to drought. The US National Climate Assessment shows that the Northeast particularly prone to heat waves, heavy downpours, and sea level rise, which the US National Climate Assessment's website goes into in greater detail. Climate Central’s States At Risk webpage on Massachusetts shows even more state-specific information on these risks we face, which they call extreme heat, inland flooding, and coastal flooding.
How Does Climate Change Impact Life On Earth?
Most species on Earth, including humans, are accustomed to the climate as it has been since the last glacial period ended over 10,000 years ago. However, anthropogenic GHG emissions are setting the stage for rapid and severe changes to the climate, faster than we can easily adapt to. These changes can lead to increased deaths and damages from a variety of causes, such as extreme weather events, lower crop yields, increased geographic and temporal reach of vector-carried diseases, infrastructure damage, and the escalation of a conflict that arises from these increased insecurities that the world’s population shall face.
What Are We Doing About It?
It is in our best interest to reduce climate change and thus reduce the risk of these adverse effects. The ways in which we are reducing our greenhouse gas emissions are laid out in our Climate Action Plan. Our Climate Action Plan Steering Committee is following this plan to guide our transition towards net zero emissions of GHGs by 2050. We are also building research, education, and outreach programs that inform our students, communities and larger society about climate change.
Our goal for net-zero GHG emissions by 2050 is best explained by the concept of carbon accounting. Carbon accounting is both similar to and better explained by financial accounting. In basic financial accounting, you gain money through income and lose money through expenses. If your income equals your expenses, you maintain the same amount of money that you started with.
In carbon accounting, our net GHG emissions are a product of both GHG sources (such as burning fossil fuels) or sinks (such as trees taking in carbon dioxide). In order to more effectively achieve net-zero GHG emissions, we are tracking how many GHG emissions each of our campus operations account for. For this tracking, we convert the total emissions of our campus operations into a common currency, called “metric tons CO2 equivalent”.
Our sources currently outweigh the impact of our sinks of GHGs, so we are working to reduce our sources and increase our sinks so that our sources and sinks at minimum equal each other by 2050. However, in order to actually reverse global warming and bring it back to pre-industrial conditions, we need to work together with everyone else on Earth to ensure that net sinks outweigh net sources. Therefore, we are working to achieve net zero emissions as soon as possible!
What This Looks Like In Practice
A lot of our work involves reducing emissions from transportation, electricity, and heating of our buildings, which are our major sources of GHG emissions. This work has covered a multitude of topics, ranging from purchasing energy efficient appliances to the creation of our FreeWheelers bicycle program.
We are working to disincentive deforestation and unsustainable farms by purchasing from more sustainable companies instead. In addition to this, we are increasing GHG sinks on campus by increasing natural habitats and organically-produced agricultural sites on campus.
We have implemented water-saving technologies to reduce our impact on the Merrimack River, which feeds a crucial carbon sink (the ocean). And lastly, we are working to reduce, reuse, and recycle waste on campus, to reduce our reliance on GHG sources and further reduce our pollution of GHG sinks.
However much we have already done, we can always use more help in making the University more sustainable. If you have any ideas of ways to help in this cause, please email us at email@example.com or apply online to the SEED Fund!