top of page
Here's some facts.
What's actually happening? What does it mean?
In this article I want to outline some of the facts about climate change. This is by no means all of the information on the topic, but rather an overview of some of the changes happening to the world around us. All references in this article correlate with the sources page.
facts: Work
When I began researching for this project, I asked people what they knew about climate change. Some subjects had a very thorough understanding of the topic, others could name a couple of impacts such as melting ice or higher temperatures. For those who were less familiar with the subject, I noticed that their understanding of climate change was more broad than specific; they understood the overall concerns and consequences, but were less sure of how or why these impacts are occurring.
To address this gray area, this article outlines some of the prominent impacts of climate change to show why they’re happening and how they’re connected.
facts: Text
Climate change and global warming
facts: Image
Let’s start with some definitions. Climate change and global warming, though often used interchangeably, have different implications and related concerns.
Climate change is the long-term alteration in Earth’s climate and weather patterns (1).
Global warming refers to the long-term heating of Earth’s climate system primarily due to human activities (2).
Global warming is intimately linked to climate change: it’s one of the alterations in the condition of our planet.
The main cause of this global increase in temperature is attributed to what’s called the greenhouse effect. Gases in the atmosphere such as water vapor, carbon dioxide, methane, and nitrous oxide let in light from the sun, but trap some of that heat within Earth’s atmosphere. The “greenhouse” that is Earth’s atmosphere is what makes the climate on our planet livable (3). We do need some heat to be trapped to maintain our climate, but with more greenhouse gases in the atmosphere, more heat is trapped, unable to be released back into space. With nowhere to go, the temperature on Earth slowly has risen.
facts: Text
Temperature
facts: Image
So why are these greenhouse gases building up in the atmosphere? There are two main reasons for this increase:
1. Natural events.
There are many naturally occurring events that contribute to changes in the climate. For example, the Little Ice Age that affected Europe and North America from around 1650-1850 is linked to a decrease in solar activity paired with an increase in volcanic activity at the time (4). However, current global warming cannot be explained by changes in energy from the sun. “If the warming were caused by a more active sun, then scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead, they have observed a cooling in the upper atmosphere, and a warming at the surface and in the lower parts of the atmosphere. That's because greenhouse gases are trapping heat in the lower atmosphere” (4). These events, such as variations in solar radiation, volcanic eruptions, and large scale weather patterns like El Niño only account for around 2% of recent warming (3).
2. Human activity.
Additional greenhouse gases in the atmosphere as a result of human activities ends up being the driving factor increasing the Earth’s temperature. We release greenhouse gases through the burning of fossil fuels like coal and oil, manufacturing, pollution, farming and raising animals for livestock. With an ever-growing population and industrial world, the amount of resources we use and, in turn, the amount of greenhouse gases we release, are increasing.
It’s true that the Earth’s climate has fluctuated in the past––global temperatures have historically risen and fallen––but the overall level of carbon dioxide in the atmosphere has never been close to what it is now. Currently, Earth’s atmospheric carbon dioxide level is around 400 parts per million, a change we’ve seen happen in only the last 150 years (3). Human activities like burning fossil fuels and agriculture have increased the amount of carbon dioxide in the atmosphere by more than a third since the industrial revolution (3).
The earth’s temperature has increased by 1º Celsius since the pre-industrial era, beginning around 1900 (2). However, this global rise in temperature can be an area of confusion. A global rise in temperature of 1º Celsius does not sound like much, but that is because it is an average. This is because different geographic locations are impacted differently; some places, such as the poles, have experienced much greater increases in temperature, whereas other places have not felt such drastic changes. Summer in midwest North America may not feel much different, but summer in the Arctic has become a whole new world with devastating impacts on those that live there.
facts: Text
Ice
facts: Image
Ice melting and the livelihood of the polar bears are common subjects in conversation about climate change, but let’s take a closer look at some of the impacts.
I’ll talk about two kinds of ice here: sea ice and ice sheets. Sea ice is formed from the salt water of the ocean and it can fluctuate with the seasons. Ice sheets, also including glaciers, are formed from fresh water and snow. Ice sheets are continental (but can extend onto the ocean as ice shelves) and are more permanent (5).
With warmer temperatures from increased greenhouse gases, the vast amount of ice that covers the polar regions has decreased dramatically. Again, Arctic sea ice naturally fluctuates throughout the year; September is when sea ice is at a minimum. But that minimum has seen a steep decline: “summer sea ice in the Arctic has reduced by 40% in 40 years” (6). Ice sheets in Greenland and Antarctica have seen declines as well: the mass of ice in Antarctica has decreased by 148 billion metric tons per year, and in Greenland by 279 billion metric tons per year (7).
facts: Text
facts: Image
The loss of sea ice and ice sheets impacts more than the polar bears. The ice covering the poles reflects sunlight off its white surface to help cool the whole earth (6). With less of this ice, less of that heat is expelled from the atmosphere. And those billions of tons of ice that are melting have to go somewhere.
That place is the ocean.
facts: Text
Oceans
facts: Image
Rise in sea level can be attributed to two major factors: added water from melting ice and the expansion of seawater as it warms (8).
Ice exists––and melts––in huge quantities. Antarctica’s ice sheet alone varies between one and four miles in thickness (9). More water is added to the ocean as these massive amounts of ice melt, which leads to other side effects. For example, coastal U.S. cities such as New York City, San Francisco, and New Orleans are at risk for flooding with a rising sea level (9).
Continental conditions are subject to more change in the future, but there are already major changes happening in the ocean now. Unlike melting sea ice, melting ice sheets are comprised of freshwater. This melting ice adds tons of freshwater to the ocean, thereby altering its salinity (9).
That’s not the only change, though. Remember the greenhouse effect? It also affects the ocean. For years, the ocean has absorbed carbon dioxide. With more and more heat trapped in the Earth’s atmosphere, the oceans have been forced to take in more of these greenhouse gases, causing a buildup of carbon dioxide in the water. Global air temperature had been relatively stable until the 1990s, but this was because the ocean had been absorbing the excess heat, masking our impact (6). Now, the ocean is unable to absorb all of the excess heat in the atmosphere.
So, when it comes to absorption, the ocean has two roles: taking in excess carbon dioxide and excess heat. The ocean ends up accounting for most of these excesses as the planet continues to warm. “The top few meters of the ocean stores as much heat as Earth's entire atmosphere” (10). Having so much heat in this very top portion of the ocean becomes a problem for the food chain.
Algae and plankton, which are at the very bottom of the food chain, live toward the ocean’s surface where they are able to absorb energy from the sun. Smaller organisms, such as krill, eat the plankton, many fish and even whales then eat the krill––the food chain goes up from there as bigger fish eat smaller fish and so on (10). These small organisms at the bottom of the food chain are the foundation of the whole ocean system. Without them, balance is threatened. And warmer ocean temperatures are threatening that balance. Krill reproduce in cold waters near sea ice toward the ocean’s surface, so with less ice and higher water temperatures, krill populations––and the entire food chain––are at risk (10).
When ocean conditions change, the animals that live there have to change, too. If they are unable to change, they face death. Altering the salt content and temperature of the oceans would be like changing the composition of the air we breathe––it’s detrimental for the organisms of this environment. As a result of climate change, overfishing, pollution, and damage to habitats, marine populations have declined by 49% (11). From plankton to blue whales, all life is impacted.
In the late 1990s and early 2000s, a phenomenon known as coral bleaching was identified. Once rich, vibrant reefs were turning white. This bleaching happens when the algae that covers the corals’ surfaces is expelled, leaving behind white skeletons of the coral (6). “At first, the cause of the [coral] bleaching was a mystery. But scientists started to discover that in many cases where bleaching occurred, the ocean was warming” (6). In warmer waters, the algae cannot conduct photosynthesis and the corals lose their food source (10). The loss of coral reefs is devastating for ocean environments; coral reefs occupy just 0.1% of the ocean floor, but are home to 25% of all marine life (12).
The impacts of our changing climate on the ocean are profound. The Earth’s changing conditions put marine populations––a major food source for humans––at risk.
facts: Text
On land
facts: Image
Just like the animals of the ocean face adverse changes, so do we here on land.
The issue is that we feel these impacts differently around the world, so it can be difficult to pinpoint why these things are happening. Below is a summary of the regions of the United States and common effects related to climate change that are experienced there as identified by NASA.
Northeast. Heat waves, heavy downpours, and sea level rise pose growing challenges to many aspects of life in the Northeast. Infrastructure, agriculture, fisheries and ecosystems will be increasingly compromised. Many states and cities are beginning to incorporate climate change into their planning (13).
Northwest. Changes in the timing of streamflow reduce water supplies for competing demands. Sea level rise, erosion, inundation, risks to infrastructure and increasing ocean acidity pose major threats. Increasing wildfire, insect outbreaks and tree diseases are causing widespread tree die-off (13).
Southeast. Sea level rise poses widespread and continuing threats to the region’s economy and environment. Extreme heat will affect health, energy, agriculture and more. Decreased water availability will have economic and environmental impacts (13).
Midwest. Extreme heat, heavy downpours and flooding will affect infrastructure, health, agriculture, forestry, transportation, air and water quality, and more. Climate change will also exacerbate a range of risks to the Great Lakes (13).
Southwest. Increased heat, drought and insect outbreaks, all linked to climate change, have increased wildfires. Declining water supplies, reduced agricultural yields, health impacts in cities due to heat, and flooding and erosion in coastal areas are additional concerns (13).
These highly variable and extreme conditions occur for a few reasons. Changes in temperature can be attributed to added greenhouses gases in the atmosphere, but also to changes in the oceans. The ocean currents and the temperature of the waters they carry impact the weather we experience on land. The large-scale currents at the surface of the ocean are driven by global wind systems and are fueled by the sun’s energy (14). These currents influence climate around the globe; they help transfer heat from tropical to polar regions, thereby impacting weather on the nearby land (14).
For regions that are experiencing high rates of warming, there are an increased number of drought periods. With these higher temperatures, moisture in the soil is reduced (13). These conditions make it easy for wildfires to start.
Other disastrous events, such as hurricanes, can be more difficult to analyze. We do know that the intensity, duration, and frequency of hurricanes has increased since the 1980s, however, the relative contributions of human and natural causes in relation to these increases is still uncertain (13). Regardless of the responsibility of humans and/or nature with these storms, these devastating storms continue to increase and impact regions around the world with serious damage and flooding.
With such variable and extreme conditions, the food industry then feels an impact. Longer frost-free periods due to increased temperatures impact the length of agricultural growing seasons, the ability of certain plants to successfully grow in the wild, and availability of food sources for animals (13). But food production has its own impacts on the environment, too. The raising of livestock for food releases large amounts of methane into the atmosphere. Methane, like carbon dioxide, is a greenhouse gas. However, methane is much more potent than carbon dioxide, so with more of it in the atmosphere, global warming is amplified (15).
facts: Text
To sum up
facts: Image
Human activities like burning fossil fuels and raising animals for food release more greenhouse gases into the atmosphere. More greenhouse gases in the atmosphere causes temperatures to increase. Higher temperatures cause ice to melt and the oceans to warm. Melting ice means that the ocean levels rise, and warmer waters affect aquatic life and ecosystems. Changing oceans and higher temperatures impact the conditions experienced on land.
Look at any of these events on their own and it may not be a cause for concern. But when you look at the whole picture, they are all connected, and they all relate back to humans driving an increase in Earth’s global temperature.
These are facts, this is the science. But science isn’t the only one with a stake in this issue. Next, we’ll take a look at some of the opinions on the topic of climate change.
facts: Text
facts: Text
bottom of page