Climate Change: What is happening and how bad is it?

6 minute read

Updated on: 18 Jun 2020

By how much have temperatures risen

Our planet is rapidly changing, and it’s not for the better [ref]. Earth’s average temperature has increased by about 1.1°C since pre-industrial times [ref] (1850-1900 [ref]). Take a look at this graph.

Image of Global Temperature rise since 1850

Global Temperature rise since 1850 [ref]

Keep in mind that this is the average. Temperatures have risen by more in some places and less in others [ref]. Some misleading sources might cherry-pick specific examples to support incorrect claims (in both directions).

Image of 2019 global variation in temperature

2019 global variation in temperature [ref]

This map shows how the January to June 2019 temperatures compared to the 1981-2010 average for the same months [ref]. Whilst some parts of the Earth were cooler, most were warmer, with places such as Siberia being 4-5°C hotter [ref]!

Average warming of 1.1°C doesn’t sound like much. But the small change in average global temperature has dramatic effects on the climate as a whole [ref]. This increase of the average temperature is what we call global warming. Climate change includes global warming as well as a truck load of other effects [ref].

What are the effects of climate change?

Heatwaves are becoming more common and intense [ref1,ref2]. So much so that they made July 2019 the hottest month on Earth since records started in 1880 [ref1,ref2,ref3].

While some droughts got more severe [ref1], there is limited evidence that droughts have already become worse overall [ref1,ref2], but they will in the future [ref1,ref2,ref3].

Image of Future droughts

Future droughts [ref]

The last 5 years have seen an average global sea level rise of 5mm per year [ref]. This again may seem like a small change, but it is already having destructive effects [ref].

Image of Bangladesh flooding

Bangladesh flooding [ref]

Just 0.5 metres of total sea level rise would affect 800 million people living in 570 coastal cities across the globe by 2050 [ref].

Image of Future flooding of coastal cities

Future flooding of coastal cities [ref]

This map shows cities with 10 million inhabitants or more, which are expected to suffer from this [ref].

Image of Existing effects of climate change

Existing effects of climate change [ref1,ref2,ref3,ref4]

25% of species are currently threatened with extinction (but not extinct yet). Importantly, this is not only due to climate change - problems like deforestation and hunting are important too [ref].

Why is this happening?

We want to stop this from happening! But in order to know how to tackle climate change, we first need to understand why it happens. The answer is simple: climate change is caused by humans emitting greenhouse gases like carbon dioxide (CO₂) and methane (CH4) into the atmosphere [ref].

Greenhouse gases ‘trap’ heat in the atmosphere [ref1,ref2]. A certain amount of various greenhouse gases is in the atmosphere naturally - without them the Earth would be covered in ice [ref]!

Image of The sweet-spot for greenhouse gases

The sweet-spot for greenhouse gases [ref]

But because humans are producing extra greenhouse gases, mostly by burning fossil fuels like oil, coal, and gas [ref1,ref2,ref3], the Earth is becoming warmer and warmer [ref].

Generating energy (for electricity, heating, transport, manufacturing and more) is responsible for 74% of greenhouse gas emissions [ref]! We need to solve this.

How fast do we need to act?

To limit the negative effects of climate change, the world’s governments have agreed to aim to keep global warming to no more than 2°C above pre-industrial levels, and ideally to just 1.5°C [ref] (remember, we already have 1.1°C of warming - so there are just 0.4°C left!). This would need highly ambitious reductions in CO₂ emissions. Sadly, humanity does not yet have any concrete plans on how to achieve that.

Image of Required emission reductions

Required emission reductions [ref]

The dashed line shows how emissions are predicted to increase in the future [ref]. The green line shows that emissions need to decrease by 7.6% each year between 2020 and 2030 in order to be on track for the 1.5°C goal [ref1,ref2]. Clearly, we are well off track.

Can we continue to allow emissions to increase? 11,000 scientists have signed their name to say no: we are facing a climate emergency and things have to change [ref]. So, what should we do? The next chapters will give you some important frameworks to find realistic solutions with a high potential. The courses that follow will introduce those solutions in greater detail.

Next chapter!