In this article, we give an overview of climate change, including the main causes, negative impacts, and how to prevent the climate crisis from destroying the planet.
By Rhiannon Wardle
Climate change has been a part of everyone’s vocabulary for the past half a century or so, but in recent years it’s become even more of a global issue. Warnings from concerned scientists, celebrities and activists about climate change appear in the news, TV, books and social media. At this stage, it’s difficult to deny that it’s a very real phenomenon. What’s more, humans are undoubtedly speeding it up.
However, it can be difficult to fully understand and engage with such an enormous topic, and additionally, it’s easy to become desensitised to repetitive warnings. With that in mind, we’ve written this guide to climate change to help you understand the basics and make a difference.
In this article, we discuss what climate change means, why we talk about it so much and the main causes. After that, we explore the impact of climate change on the planet and how you can enact change on an individual and societal level.
What is climate change?
Climate change is essentially a long-term shift in the regular weather conditions and temperature of a certain region, but we normally talk about it on a global scale. Not every climate is being affected in exactly the same way, but we are seeing large shifts in climate across each part of the world.
While climate change has occurred since the dawn of time, we usually use the phrase to talk about the rise in global temperatures from the middle of the 20th century to the present day. This is because Earth has warmed by just over 1° Celsius since 1880, but two-thirds of this warming occurred after 1975.
This points to a large acceleration in global warming due to an increased use of fossil fuels in the post-War era, and this has only continued to accelerate. In fact, sixteen of the seventeen warmest years on record have occurred during the 21st century.
Global warming and the greenhouse effect
Now that we know “climate change” generally refers to the way global warming is affecting the planet, it’s time to delve deeper into how global warming works. In our Introduction to climate change open step, Keith Shine from the Department of Meteorology at the University of Reading discusses the greenhouse effect.
He explains how human activity is creating an increase in what we call greenhouse gases, and these largely consist of carbon dioxide, methane and nitrogen oxide. Carbon dioxide is the most problematic gas and is usually emitted from the burning of fossil fuels such as coal, oil and gas. Methane is created from agricultural systems, and nitrogen oxide is also emitted by different agricultural sources.
The greenhouse effect is actually a natural and necessary process, where greenhouse gases in the atmosphere absorb solar radiation in the form of heat, therefore heating up the Earth. If this didn’t happen, Earth would have a temperature of -20°C. However, the amount of greenhouse gases in the atmosphere means that more and more heat is being absorbed, which in turn heats up the planet more than is necessary.
Why are we always talking about the climate crisis?
It may sometimes feel like the climate crisis is always in the news, but we’re powerless to help, which can make the constant stream of information feel overwhelming and even fear-mongering at times. However, there’s a good reason why everyone’s always talking about it.
Many scientists and experts believe that the planet may reach certain ‘tipping points’ where elements of climate change will become completely irreversible or trigger positive feedback loops. One example of a potentially irreversible change would be the melting of ice sheets, as this will have a huge impact on sea levels and the climate.
It is therefore vital that we try and pull together to make changes before the Earth reaches these tipping points and it’s too late. We don’t want to become totally powerless and risk our beautiful planet. The time to push for change is now, before we tip the scales in the wrong direction. To learn more, try our Tipping Points: Climate Change and Society course by the University of Exeter.
What are the main causes of climate change?
We’ve already discussed how climate change today refers to global warming as a result of more greenhouse gases in the atmosphere. In our past changes in climate open step by the University of Bergen, experts discuss ice core data from Antarctica and Greenland.
They state that in the past 150 years, atmospheric concentrations of CO2 and methane have exceeded all of the natural variations over the past million years. In addition, the concentration of carbon dioxide has increased by nearly 40% since the pre-industrial era. All of this begs the question, what exactly is causing all of this carbon dioxide in the first place?
Burning fossil fuels
The three main types of fossil fuels are coal, crude oil and natural gas. Fossil fuels are extracted using a range of methods, including mining, drilling, fracking and acidizing. All of these methods are harmful to the environment, whether through destroying ecosystems and landscapes, causing deadly oil spills, increasing air and water pollution and creating greenhouse gases.
Our consumption of fossil fuels has dramatically increased over the past half-century, around eight-fold since 1950, and doubling since 1980. This reliance we’ve developed on fossil fuels can help to explain the abundance of atmospheric CO2 and Earth’s warming.
As we explore in our blog post about whether eating meat is bad for the environment, deforestation is directly and indirectly caused by the production of meat. Vast areas of the Amazon rainforest are being cleared to make room for cattle farming and the production of soybeans for animal feed.
What’s worse is that often these areas of forest are burned down, which causes a huge amount of carbon dioxide to be released. Not to mention, forests are natural consumers of C02 and releasers of oxygen, so destroying large areas of forest is very detrimental to the climate.
The agricultural industry
This is linked to the previous point about deforestation, but the agricultural industry creates more environmental problems than just the destruction of forests. Raising livestock leads to large amounts of methane being released, decaying manure also releases methane, and many fertilisers used in soybean production produce nitrous oxide emissions.
This means that the agricultural industry is boosting the amount of greenhouse gases in the atmosphere by a pretty large amount. Additionally, agriculture can create other issues for Earth, including increased water usage, soil degradation, chemical pollution and biodiversity loss.
Although humans are responsible for the increase of greenhouse gases being released into the atmosphere, there are natural causes of climate change too. Met Office lists four of the main natural causes of climate change on their website:
- Milankovitch cycles. These cycles are to do with the tilt of the path and axis that Earth journeys on around the sun. They affect the amount of sunlight falling on Earth which can impact the temperature.
- El Niño Southern Oscillation (ENSO). El Niño describes the warming of Pacific Ocean temperatures, and ‘La Niña’ describes the cooling of them. In certain years, these weather patterns can affect the global temperature and some weather patterns temporarily.
- Solar irradiance. The energy from the sun can change from time to time, and this can affect Earth’s temperature. However, it’s never actually changed the climate.
- Volcanic eruptions. Volcanoes actually have an interesting effect on the climate – while eruptions release carbon dioxide, which warms the Earth, they also release aerosol particles that cool it simultaneously.
What is the impact of climate change?
The impact of climate change is far-reaching, affecting our environment, fellow living creatures and society. Here, we talk about some of the most major consequences of climate change, though there are plenty more we won’t be mentioning.
Climate change is causing more extreme weather, as we’ve seen from recent events such as the flooding and bushfires in Australia, more intense heat waves, stronger hurricanes, and the California wildfires. A lot of these extreme weather events are caused by the increasingly high temperatures and consequential higher evaporation and precipitation rates.
For example, Australia’s natural rainfall patterns already vary dramatically, but if you add a warming planet and warming ocean to the mix, the chance for extreme rainfall increases. Heavy rain is more likely because the amount of water that Earth’s lower atmosphere can hold increases by roughly 7% for every 1℃ that the planet warms by. Furthermore, warmer ocean surfaces increase the evaporation rate, which creates moist air and more rain.
A devastating report by the UN suggests that roughly 1 million animal and plant species are threatened with extinction, which is more than we’ve faced before in human history. What’s more, is that many of these mass extinction events could happen within decades.
The report shows that the number of native species in land-based habitats has fallen by 20% since 1900, and there are threats to 40% of amphibian species, 33% of reef-forming corals and over a third of marine mammals. These numbers are dangerously high and threaten the biodiversity and beauty of the planet.
Research in a review by the Royal Society shows that most species who have gone locally extinct or declined in population have done so as an indirect result of global warming. Rather than not being able to tolerate higher temperatures, climate change was found to be influencing interactions between species, for example, by reducing prey populations for predators.
Melting ice caps
About 10% of land on Earth is currently covered in glacial ice, with 90% of this in Antarctica and 10% in Greenland. Since the early 20th century, glaciers have been melting rapidly due to the increasing temperatures on Earth. The temperatures in the poles are affected more than the Earth’s average temperature, meaning that the likelihood of ice caps melting is even higher.
The melting of ice glaciers is devastating because it has the ability to change ocean currents and increase sea levels. Extremely cold glacial-melt water going into warmer water slows down the ocean currents, which can have an impact on plankton that lie at the bottom of the ocean food chain. Rising sea levels increase the likelihood of floods, habitat loss and soil erosion.
Even if we curb emissions significantly in the future, we’ve already done enough damage to make sure that one-third of the remaining glaciers will melt by 2100. However, if emissions continue to rise at the current rate, we could be witness to an ice-free Arctic in the summer of 2040.
Changing wildlife habitats
This ties into multiple causes that we’ve previously explored, such as ocean warming and deforestation. One good example of a wildlife habitat changing and being destroyed is ocean acidification. As we explored in our blog post on ocean sustainability, the amount of CO2 in the ocean is increasing as the amount in the atmosphere rises.
This is because the ocean absorbs 30% of C02 in the atmosphere, so is directly affected by our increased use of fossil fuels and agricultural practices. More carbon in the ocean results in more hydrogen ions and a lower overall pH in the ocean. This is ocean acidification and has many negative consequences for marine life, such as making it hard for shellfish and coral to build and maintain their shells or structures.
What is being done to combat the climate crisis?
You may be wondering at this point, what are the world leaders doing to combat climate change? In our Climate Change open step by Unesco, experts discuss some of the attempts that world leaders have made to deal with the crisis.
Despite most leaders now believing that humans contribute greatly to climate change, it’s historically been difficult to get nations to agree to global policy changes. For example, the US Senate did not ratify the 1997 Kyoto Protocol, an international treaty about climate change, and the 2009 UN climate summit in Copenhagen failed to set basic targets for reducing global emissions.
In Paris, there was a successful international agreement made in 2015. The Paris Agreement is a legally binding international treaty on climate change, adopted by 196 Parties. The main goal of the treaty was to limit global warming to below 2, and preferably to 1.5 degrees celsius.
How can we protect and save the Earth?
The most important lesson to learn from all of this is that we need to take action in order to protect the planet and create climate change solutions. To make this idea a little less daunting for you, we’ve provided you with some tips on some achievable steps you can take to help tackle climate change.
Switch to renewable energy sources
We’ve been harnessing the power of nature for centuries, but commercial use of renewable energy is a more recent feat. While there are some challenges that come with using renewable energy, there’s also a lot to celebrate. We have an infinite amount of them, we don’t have to rely on other countries for supply, the sector is continuing to grow and create more jobs, and they don’t have a disastrous environmental impact like fossil fuels.
In our blog post on renewable energy, we talk about different energy sources, including wind, solar, hydroelectric, geothermal, biomass, tidal, and even nuclear energy. While not all of these will be suitable to switch to, and it’ll depend on the climate where you live, we hope this article will inspire you to look into your options.
Adopt sustainable living practices
In a practical sense, sustainability is any action or process we perform that causes little or no harm to the natural world or living creatures, including other humans. It’s all about finding ways to meet the demands of life without causing detriment to society or compromising future generations.
In our blog post about sustainable living, you can learn about the three pillars of sustainability, the UN’s Sustainable Development Goals and how we can move towards sustainable living. This includes thinking about sustainable food and farming, sustainable fashion, sustainable technologies and sustainable transportation. You’ll discover that individual lifestyle choices have more impact than you realise.
Reduce your carbon footprint
As we explore in one of our earlier blog posts, your carbon footprint is the measure of the total amount of greenhouse gases released into the atmosphere as a result of your individual actions. Alternatively, you can measure the carbon footprint of an organisation or nation. This is normally measured in tonnes of CO2e.
Amazingly, only 100 companies are responsible for 71% of all global greenhouse gas emissions, which can make it seem like individual choices don’t matter. However, all of our actions and lifestyle choices have some impact on the environment, and organisations will often only change in response to customer demand. Some top tips for reducing your carbon footprint include:
- Insulate your home
- Buy energy-efficient appliances
- Use less water
- Cycle to work
Demand climate action and volunteer
Some of the most vital things you can do are to demand climate action from your local and national government, and volunteer your time with organisations that aim to make an active difference. NRDC (Natural Resources Defense Council) have some excellent tips on their website for how to take action now, and we’ve sprinkled in a few of our own:
- Find a local activism group. Check to see if your town or city has a conservation committee, sustainability circle, or any Facebook groups that support certain causes. Once you’ve found a group, make sure you attend meetings and learn about the top priorities of your fellow citizens. Then, you can alleviate climate anxiety and start making a difference.
- Make your hometown a climate sanctuary. If you fight against the use of fossil fuels in your hometown, you might find that momentum starts to build for an even bigger movement. In your newly found local group, you can choose some specific goals to pursue, from tackling food waste to water conservation projects.
- Get familiar with your government. Your local and national elected officials are meant to voice the concerns of the community, so make sure you make your voice heard. You can make phone calls to their offices, email them, sign petitions, and use social media to push for your climate goals.
- Talk about climate change. Whether you have conversations with friends and family, or you decide to give talks at work or university, our voices hold a lot of power. It can also inspire people to commit to sustainability and ending climate change when they have good role models.
Climate change is a pretty enormous issue, but we hope that this guide helped you to understand the main discussions surrounding it. If you’re interested in learning more, we have a fantastic array of courses related to climate change, sustainability and environmental challenges in general.
It may feel scary and daunting to take on such an enormous global challenge, but there are simple steps you can take to make a difference. We believe that the effort is worth it to protect nature, our fellow living creatures, and future generations.