The next environmental issue we are going to come across on this blog is one that I probably had the least amount of prior knowledge on going into this adventure. It kind of sounds like something a lot more imminently deadly than it is, something that a super villain in a movie would come up with potentially. What I am referring to here is acid rain.

Although not quite as scary as it may sound, acid rain definitely still something to be discussed in our long list of environmental problems. Acid rain is essentially rain with a significantly low pH (low pH means it is more acidic), which is caused by pollution in the air. The burning of fossil fuels is what pollutes our air and, consequentially, our rain as well. Factories contribute a lot to this issue, as well as exhaust from cars or other automobiles. These things release sulfur dioxide and nitrogen oxides into the air, which can eventually reach high enough in the atmosphere that they react with water in the clouds and produce the acidic rain.

The effects of acid rain are mostly noticed in aquatic environments, where the rain can lower the overall pH of the body of water. The acidic rain releases aluminum into the water as well. Some aquatic animals are able to tolerate changes in pH, but there is a critical level of pH for every species and once it hits that level, the species will struggle to survive. At a pH of 5, most fish eggs are unable to hatch, and at lower levels the adult fish will die. The aluminum released into the soil is also harmful to plants. That coupled with the fact that acidic clouds can cause harm to plants is the reason that areas of frequent acid rain contain a lot of dead trees. Fortunately for humans, our bodies are adapted to be unharmed by acid rain, but when the compounds in acid rain are released into the air, then they can start to cause some health problems.

There is a bit of good news surrounding this acid rain situation, though. The Clean Air Act was passed in 1990, which put regulations on emissions which pollute the air. Since then, there has actually been a decrease in acid rain, meaning the Clean Air Act really did its job. Comparing values from 1985 and 2008, the amount of rain or snow with a pH of less than 5 decreased in both concentration and frequency. Scientists are not surprised by this fact, because they understand that regulating emissions of sulfur dioxide and nitrogen oxide in the air will consequentially decrease the reactions they have with the atmosphere, which eventually lessens the problem of acid rain. This is different from almost all of the other issues on this site, because typically they just seem to get worse over time. For me at least (and hopefully for you as well), it is a breath of fresh air to be on the positive side this time. Do not get too excited though, because we still have a ways to go before this problem is no longer a problem anymore.

Although the Clean Air Act significantly helped with the acid rain problem, it does not mean that it made it go away. It is no secret that air pollution continues to be a concern in today’s world, and as a result acid rain is as well. It is still very important that we take care of our planet and be mindful of how we are impacting it. While much of the pollution comes from factories and larger sources, there are still things that we can do, even if they are minor, to help as much as we can. Energy production is a main source of air pollution, so conserving energy by doing things such as turning out the lights when you leave a room and all of those other little things we have been taught to do our whole lives can make just a little bit of a difference. Buying energy efficient appliances is something else that can decrease our impact. The biggest one is probably minimizing the amount of driving we do, because car exhaust immediately pollutes the air. Carpooling, taking public transportation, driving energy-efficient cars, or even just walking or biking somewhere are important steps to be taken.

Acid rain is not as large of a problem as it used to be, but it is still a problem nonetheless. The harm that it can cause to plants and aquatic environments is a very real concern, since so many living things can not survive if their environment is too acidic. It is our job to ensure that the impact of acid rain continues to slope downward, so that we can have a positive impact on our world.