Earth's climate has been changing at an alarming rate over the last 100 years, and many trends are speeding up rather than slowing down. This fact manifests itself in a variety of frightening and sometimes seemingly contradictory ways. To put it simply, the delicate balance that our planet's ecosystems have struck for tens of millions of years is in danger of being upended by the unprecedented concentration of carbon dioxide in our atmosphere.
A (roughly) 100,000 year climate trend called the Paleocene-Eocene Thermal Maximum - PETM happened about 55 million years ago, which is the closest global climate parallel we can look to when examining our current rate of climate change. However, the problem with this comparison can be seen below.
There is no easy way to quantify or visualize what can and will happen if the red line in the above chart continues going upward, because there has not been a climate shift like this in human history. The hard truth is - We are not not going to escape catastrophic effects of climate change entirely, even if not a single ounce of fossil fuels were used starting tomorrow.
The below paragraphs will outline some of the ways that our planet and its inhabitants will be affected in the coming decades and centuries. Many of these consequences are already happening right now, even if they do not seem to be personally impacting your life.
These effects will not be felt evenly, and often times the brunt force of climate change happens to fall on those least able to protect themselves from its devastation. It is easy for most Americans to ignore climate change currently because there is always the option to blast AC when it's too hot, to buy water filtration systems or bottled water if our public reservoirs are compromised, to take out insurance against flooding so that we don't lose all our material possessions, etc.
Climate change is a scary issue to think about, but we all have a responsibility to learn about it and try to do our part. Even if it doesn't measurably impact your life yet, think about the people who are being impacted every single day and imagine that being you or your own family. Because if we don't collectively act to stop climate change, it might be sooner than you think.
Dangerous Heat Waves
One of the most easily-linked consequences of extreme weather events to climate change is the increased occurrence of deadly heat waves. It makes perfect sense that if you're trapping more of the sun's energy beneath a heavier and heavier layer of CO2, the planet's temperatures will rise. Heat waves lack dramatic visuals of super storms, however they kill more people in the US on average every year than hurricanes, lightning, tornadoes, earthquakes, and floods combined.
More Severe Storms
The concept of warm air "holding" more water is not 100% correct as an analogy. However, global warming does make storms stronger and more unpredictable, in large part due to the amount and temperature of the water that is fueling a storm system. We're impacting the planet's natural jet streams and raising the temperatures of our oceans, which is making the severity of flooding, category 4 & 5 hurricanes, typhoons, etc. harder to deal with when we're still picking up the pieces from the last disaster.
Our planet is getting hotter, and there is not an even distribution of where moisture goes when it evaporates into the atmosphere and is then is expressed as precipitation. That means some places will get rain more frequently (like the Northeast and Midwest), while other areas will experience longer periods of drought due to higher average global temperatures. Drought (and climate change's impact on it) is harder to measure directly than something like heat waves. However, the consensus is clear among scientists is that higher global temperatures will continue to compound the effects of worldwide droughts.
loss of Food Security
Regardless of the immediate concern for not having a sufficient amount of drinking water, droughts also threaten our food production systems. In a world where the population continues to climb, being able to feed less people is a big problem. Improvements in agricultural efficiency, knowledge sharing, and scientific advances have allowed for hundreds of millions of people to be lifted out of hunger in the last 20 years. But even with the help and resources of philanthropic superheroes, it will be harder to grow staple crops if the water we set aside for agriculture is less abundant and the natural water cycle is more unpredictable, ultimately causing us to rely even more heavily on our shrinking groundwater/aquifer reserves.
Coral Reef destruction
A healthy ocean is vital to humanity's survival, as it provides us with more oxygen than anything else on Earth and seafood is the number one source of protein for over 3 billion people. One of the more devastating effects of climate change that has been gaining attention in recent years (check out Chasing Coral on Netflix) is the widespread coral bleaching that has already killed over half of the coral in the world in just the last 30 years. If projections are accurate, we are on track to lose 90% of the world's coral by 2050. Since 1 in 4 marine species count on coral for survival, that not only spells extinction for those dependent marine species, but would also be catastrophic for entire food webs, including human beings.
Worse wildfire seasons
As a result of prolonged drought conditions, shorter & warmer winters, and a longer pine beetle season, our nation's forests are more susceptible to wildfires than at any time in memory. A study done by Oregon State University showed wildfire frequency was nearly 4x what we had from 1970 to 1986. The Thomas fire of 2017 destroyed hundreds of thousands of acres alone. California has the world's 6th largest economy on its own, so the loss of that much economic potential and the subsequent funding needed for rebuilding efforts is going to be staggering. Climate change severely impacts the United States' GDP because wildfires are going to be inevitable in some of the most economically prosperous and agriculturally abundant areas in the country.
Sea level rise
Human civilization has always gravitated toward the coastline. Roughly 10% of people live less than 30 feet above sea level. And that number jumps to nearly 40% in the US. There is a ridiculous amount of currently vacant land in the world that displaced refugees could go if forced from their homes by sea level rise. However, the idealized goal of society should not just to be above water, but also for populations to survive and flourish once living there. Many of the places not currently colonized by humans are uninhabited because their conditions are too harsh, they are extremely difficult for travel, or they are bereft of natural resources that we need to survive. Also, the cost of rebuilding coastal cities on new shorelines will be astronomical and impractical if they will just need to keep moving further inland.
Global REfugee Crisis
Climate change is the biggest underlying cause of the world's refugee crisis. If you want some more proof of that, check out this article, or this one, or this one, or this one. Ok, you get it. There is a lot of research saying the same thing. But it is important to hammer home this point, because it's a big one and is projected to affect billions of people by the end of this century. Food insecurity, drought, rising sea levels & severe storms destroying coastal communities, wars over dwindling resources, and many other consequences of climate change will essentially render large portions of the planet uninhabitable for humans. And those people who are displaced will be driven to less-affected areas, putting further stress on economic safety nets and humanitarian aid budgets to the countries who decide to help.
Mass Wildlife extinction
Since the start of the 19th century (mirroring the birth of the modern oil industry...), animal species have gone extinct at a rate that is 72 times faster than expected. According to the International Union for the Conservation of Nature, only about 40% of animal species currently have no concern for extinction risk. By the end of this century, it is almost certain that 1 in 6 animal and plant species will be wiped off the planet. A more pessimistic estimate, shown in this very interesting visual from TED (2nd graph) would hypothesize that only 25% of animals on Earth today will live to see the 22nd century. Imagine the effects on our global food web if that happens.
Deforestation is both a cause of, and to a lesser extent, an effect of climate change. More of our forests are being degraded or lost because of the stress humans are putting on the water cycle and the corresponding increased risk of wildfires. However, the main culprit of deforestation is direct actions by humans. We are destroying the organisms that provide nearly 1/3rd of our planet's oxygen at a scary rate. Besides allowing us to breathe, (most) forests act as a carbon sink, soaking up the CO2 that we put in the atmosphere through fossil fuel usage or even our own respiration. So, the fact that we're destroying the very biospheres we need to regulate carbon dioxide in our atmosphere is a huge reason why climate change is actually speeding up.
The financial ramifications that climate change has on our infrastructure is astounding, and it will only compound if conditions of the climate refugee crisis continue worsening. The initial cost of upgrading our energy grids and mitigating the effects of future climate change would be very high (5th chart). However, the monetary cost of not doing so is even higher. Besides the benefits to human health and safety, upgrading to a green energy grid is the fiscally responsible long-term choice and is more conducive to job growth. Simply retrofitting US buildings to be more energy-efficient would create over 3.3 million cumulative job years alone. Wind and solar are already employing 3x as many people as coal, but special interest groups for fossil fuels continue to obstruct the global green energy revolution.
Plastic oceans are not a direct effect of climate change, however it is a worldwide ecological problem further aggravating our marine ecosystems. One issue that gets a lot of attention in the media is the giant garbage patches larger than entire countries swirled together by oceanic currents into gyres. While that is definitely not good news, it would almost seem like mother nature is sweeping up our mess for us. Unfortunately, the reality is that microplastics are everywhere in our waters. It is estimated that every square mile of the ocean has 46,000 pieces of plastic in it. That plastic is eaten by fish, then makes its way up the food chain and to our plates. A shocking report from the MacArthur Foundation found that we could have more plastic than fish in the ocean by 2050.
decreased air quality
It only makes sense that if we're adding and trapping more pollutants in our atmosphere, while simultaneously reducing the acreage of our forests, our air quality is going to suffer. NASA, the CDC, the American Lung Association and many other public health organizations have all warned of the effects of decreased air quality as a result of fossil fuel pollution and climate change. Different regions of the world will be affected to varying degrees, but we don't have to look far to see a cautionary tale. China's capital city of Beijing is now having to adjust urban planning and architectural efforts in order to account for an inhospitable atmosphere.
Increased risk of disease
On top of all the other effects that global warming has on humanity, it also makes us (and other plants/animals) more vulnerable to diseases. Besides the decrease in air quality from added fossil fuel pollutants and the increased levels of allergens filling our lungs, humans are going to be more susceptible to diseases transmitted by mosquitoes, ticks, mice/rats, birds, and other species that are able to pass on bacteria, viruses, and parasites to human beings. This is because the conditions in which these harmful organisms and pathogens thrive are becoming more prevalent in our warming world. From a World Health Organization report in 2996 (McMichael, et al.) - "Many of the most common infectious diseases, and particularly those transmitted by insects, are highly sensitive to climate variation."