Scientists have been warning about the potential threats of climate change for decades. While this issue was ignored for quite some time, there has been a growing concern about the effects of climate change over the past few years, making this global threat a common topic of discussion.
That’s how we started hearing the phrase “we should limit global warming to two degrees” more frequently. But what is the two-degree target? How can just two degrees cause so much trouble? Although 2 degrees may not sound significant, it can indeed change the world as we know it.
Just think about this: Doesn’t your body react differently when your temperature goes from 37 degrees Celsius (98.6 degrees Fahrenheit) to 38.5 degrees Celsius (101.3 degrees Fahrenheit)?
In this article, we’ll explain in simple terms what the two-degree target is and why it is important to limit global warming to 2 degrees. So, let’s jump right in!
How 2° C Became a Target
Before we delve into the two-degree target, you should know what the Paris Agreement is and how it is related to climate change.
According to the United Nations Framework Convention on Climate Change, the Paris Agreement is a legally binding international treaty on climate change and it was adopted by 196 Parties at the UN Climate Change Conference (COP21) in Paris, on December 2015.
What is the Two Degree Target?
Acknowledging the importance of collaborative actions to fight climate change, the Paris Agreement aims to strengthen the global response to this issue. With the two-degree target, Parties commit to taking relevant actions to keep the global temperature rise well below 2 degrees Celsius (about 2.7 degrees Fahrenheit) above pre-industrial levels. But more importantly, they commit to pursuing efforts to limit the temperature increase even further to 1.5 degrees Celsius (about 3.6 degrees Fahrenheit).
Believe it or not, there’s a huge difference between 1.5°C and 2°C of global warming. If you would like to understand why, we’ll explain these differences later in this article, so keep reading!
Why is the Two-Degree Target Such a Big Deal for the Planet?
If the Earth gets 2 ºC above pre-industrial levels, extreme weather conditions such as heat waves and storms will become the norm, water scarcity will worsen, coral reefs and many other species will most likely go extinct, far more population will face food scarcity, and that’s just the beginning!
What is Causing Climate Change?
Scientists agree that human actions are the predominant force behind climate change. Over the past 150 years, we have been burning fossil fuels non-stop to generate electricity, move from one place to another, manufacture the products we use, and much more. All of these activities release an enormous amount of greenhouse gases into the atmosphere, which in turn makes our planet warmer and leads to more frequent extreme weather events.
To give you an idea, a “safe” level of CO2 in the atmosphere is around 350 ppm (parts per million). However, carbon dioxide concentration in the global atmosphere is currently topping 420 ppm. Even though this level is already causing a lot of trouble, it’s just the tip of the iceberg. If we don’t stop releasing greenhouse gas emissions, this figure will keep increasing.
In fact, a United Nations report estimated that our global average temperature could reach 1.5 ºC above pre-industrial levels at any point between 2030 and 2052 if we don’t reduce our emissions.
How 2° C Became a Target
Does the IPCC ring a bell? You’ve probably heard about its reports on climate science either on the news or social media. Although the Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change, it wasn’t the first organization to bring attention to the two-degree target.
This topic has been around for a while now. In the 1970s, William Nordhaus, an economist at Yale, mentioned in several papers that a two-degree increase in the global average temperature could lead to extreme climate conditions that human civilization had never experienced before.
Several years later, a NASA scientist, brought the topic up again. In 1988, James Hansen was one of the first scientists to publicly link anthropogenic emissions to global warming. Not only did he state that the Earth was getting warmer but he also said that temperatures would keep increasing if the world didn’t reduce its emissions, which could result in “catastrophic climate change”.
Since Hansen didn’t explain in detail what might constitute “catastrophic climate change”, other scientists decided to study this topic. As a result, many other papers started to use 1 Cº and 2 Cº as references to compare how different levels of warming could impact our climate. These papers came to the same conclusion we know today: the higher the temperature rise, the greater the risks.
It’s natural to think that after these results, governments or international bodies would quickly establish an international treaty to limit global warming. But that wasn’t the case. Despite the urgent need to limit global mean temperature change, the two-degree target was formally written two decades later, during the Cancun Agreements in 2010.
And here’s where we get back to the Paris Agreement. This legally binding international treaty defines the two-degree target as the upper limit for global warming but also lists 1.5° C as a more desirable goal.
Key Differences Between 1.5 ºC & 2 ºC of Global Warming
We might think that there wouldn’t be much difference on our planet with an increase of half a degree Celsius in global temperature, which is less than 1 degree Fahrenheit. While it doesn’t sound like much, the Intergovernmental Panel on Climate Change (IPCC) report found that this slight difference would lead to far more devastating effects and it could mean life or death for many species.
So, let’s explore some of the main differences between 1.5 ºC and 2 ºC of global warming, according to the IPCC report:
- Heatwaves: With a 1.5 ºC increase in global temperature, around 14% of the Earth’s population will be exposed to extreme heatwaves at least once every five years. With a 2 ºC temperature increase, this number goes up to 37%.
- Sea Level: If the temperature increase is limited to 1.5 ºC, sea-level rise is expected to be 0.33 feet (0.1 meters) lower than at 2 ºC.
- Coral reefs: While coral reefs are projected to decline by 70-90% with a 1.5°C increase, they could go extinct in a 2°C scenario.
- Biodiversity Loss: With a 1.5 ºC increase, the report projects that 6% of insects, 8% of plants, and 4% of vertebrates will lose more than half of their climatically determined geographic range by 2100. On the other hand, a 2 ºC increase will drive these numbers up to 18%, 16%, and 8%, respectively.
- Water, health, & food: Climate-related risks to human health, such as heat-related deaths, are expected to increase at 1.5 ºC warming. Similarly, food security and water supply will also be affected. That said, these impacts are expected to worsen in a 2-degree scenario.
What Can You Do to Fight Climate Change?
As you might know by now, the “two-degree target” is just a goal to limit global mean temperature change to no more than two degrees. However, this doesn’t mean that global temperature rise will stop at this point. It could actually get worse. That’s why it’s important to take action on climate change while we still can.
How can I fight climate change at home?” You might wonder.
And that’s where we come in. At Pollenate, our goal is to help you make your household more climate resilient.
Don’t miss out on our future articles exploring the realms of climate change and sustainable gardening!