A rapidly warming world is a threat to our existence.
Why is it a crisis?
The increase in temperature is already causing more extreme weather events around the world. Droughts and flooding are more common and severe. Heat waves are more frequent and last for longer than they would without any change in the climate.
This kind of climate change already results in food and water insecurities and contributes to conflicts. There are more wildfires. Islands and low-lying countries are threatened by rising sea levels. Lives are at risk.
The speed of change is also why it’s termed a crisis. The current trend of global warming is caused by humans and it’s happening much faster than ‘natural’ climate change, which historically was due to volcanic activity or a shift in Earth’s orbit, altering the level of heat from the sun.
So, the climate has always been changing?
Yes, Earth’s climate has changed in the past. But the difference now is that the change is driven by human activity and happening faster than any change we know of in the last few thousand years.
How have we driven climate change?
Since the 1800s – when the West industrialised – the burning of fossil fuels, such as coal, oil and gas, has created greenhouse gases that trap the sun’s heat in the atmosphere. This is why we have seen rapidly rising temperatures throughout the 20th and 21st centuries.
How much has Earth warmed?
The surface temperature of the planet has risen by about 1°C (2°F) since the late 1800s. Most of that change happened over the last 40 years, so it’s an accelerating trend.
The top 100 metres of the ocean has also warmed by more than 0.33°C (0.6°F) since 1969.
That doesn’t sound like much. Or is it?
This change is in the climate (long term) rather than weather (day to day), and it’s a global average across many years. It might not sound like a lot, but on a climate level, it’s big. It’s already enough to be causing a major shift across various environments.
For example, ice sheets are shrinking, snow cover is decreasing and glaciers are retreating.
Sea levels have risen by about 20 centimetres or eight inches in the last 100 years. And over the past two decades, the rate has been double that of the 20th century.
Do climate scientists agree about why Earth is warming?
Yes. An overwhelming majority of scientists (around 97%) who study the climate accept that Earth is warming due to human activities. This is because the evidence is so clear – and that’s how scientists make their conclusions, by analysing the data.
“Climate change is real. There will always be uncertainty in understanding a system as complex as the world’s climate. However there is now strong evidence that significant global warming is occurring… It is likely that most of the warming in recent decades can be attributed to human activities.”
Joint statement from 11 international science academies
Why do some people not believe in climate change?
For some big businesses, it’s in their interest to play down the seriousness of the climate crisis – particularly those who make their money directly or indirectly from fossil fuels.
The climate crisis requires us to change the way we live. For many people, it’s easier to deny it’s happening than to accept such change. And there’s a lot of disinformation out there, too.
But the facts – and the physical effects of climate change – speak for themselves.
“Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact.”
Intergovernmental Panel on Climate Change (IPCC)
What does the future look like?
If we continue as we are, extreme weather events will worsen across the world.
By the 2040s, heat waves are predicted to become four times more frequent than today.
Droughts will be more severe and last for longer. As a result, crop failures will likely become widespread, leading to a global food crisis. A loss of biodiversity due to the changing climate may also impact food availability.
With drier conditions, wildfires will be more common and more dangerous.
Rising temperatures have been shown to cause heavy rain due to warmer air holding more moisture – so flooding will be more frequent. And droughts can make flooding worse, because the earth hardens and has reduced vegetation coverage, making it slower to absorb rainwater.
Coral reefs will die, and some island nations may not survive rising sea levels.
Poorer countries will typically be most affected, because of their geographical positions, weaker infrastructures and lack of resources to prepare for climate change. This is often called ‘climate injustice’, as these countries have contributed so little to the climate crisis.
What’s been done so far?
The Paris Agreement was signed by 196 parties in 2015. It’s a legally binding international treaty that commits most countries in the world to start reducing their emissions and limit global warming to at least 2°C (3.6°F) and ideally to 1.5°C (2.7°F).
The bottom line is that not enough has been achieved to limit global warming. An increasingly number of countries have set targets, but more needs to be done to meet them.
What’s the fix?
Governments need to take immediate action to honour their commitments to reducing global warming.
- We must reduce greenhouse gas emissions by 45% by 2030 and reach net zero by 2050 – the longer we fail to reduce emissions, the more extreme each annual round of cuts need to be (and it will cost more, too). Decarbonisation can be achieved by switching to renewable energy sources like solar and wind, for example.
- We must protect and restore ecosystems that hold carbon – for example, wetlands and forests.
- Investing in nature-based solutions and sustainable land-use systems (for example, REDD+ or climate-smart agriculture) not only helps tackle the climate crisis, it could create 120 million new jobs and US$4.5 trillion in new business opportunities every year by 2030.
- Poorer and developing countries should be financially supported in coping with climate change and decarbonisation, having contributed so little to the crisis and most having not had the same opportunities as the West to benefit from resource exploitation.
It’s important to roll out strategies to cope with climate change, because regardless of emission cuts, we will still see the effects of warming in the immediate future.
For example, the World Bank has put together a guide for dealing with floods and droughts, called the EPIC Response.
What can we do as individuals?
As citizens, we can put pressure on our governments to deal with the climate crisis.
We can vote for politicians with a plan, attend protests, write to local leaders and sign petitions.
And on a smaller level, we can focus on reducing our own carbon footprints.
And don’t underestimate spending power – how we spend our cash sends a clear message to businesses in terms they understand. Support those who are actively decarbonising and reducing their impact on the world (not just buying carbon credits).
Above all, we must keep the faith. As the UN’s Secretary-General António Guterres said, “The climate emergency is a race we are losing, but it is a race we can win.”
Sources
Climate Change, Global increase in record-breaking monthly-mean temperatures
Energy Innovation, The Costs of Delay
Environmental Research, Consensus on consensus: a synthesis of consensus estimates on human-caused global warming
Environmental Research, Historic and future increase in the global land area affected by monthly heat extremes
Indiana University Bloomington, Do extreme floods and droughts cause more extreme floods and droughts?
International Growth Centre, Does climate change cause conflict?
IPCC, Climate Change 2021: The Physical Science Basis
IPCC, Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC, IPCC Special Report on Climate Change and Land
NASA Global Climate Change, Drought Makes its Home on the Range
NASA Global Climate Change,Evidence
NASA Global Climate Change, Scientific Consensus: Earth’s Climate Is Warming
New York Times, The Science of Climate Change Explained: Facts, Evidence and Proof
The Conversation, Climate change is making flooding worse: 3 reasons the world is seeing more record-breaking deluges and flash floods
The World Bank, An EPIC Response: Innovative Governance for Flood and Drought Risk Management
UN Climate Change, The Paris Agreement
UN Climate Change, For a liveable climate: Net-zero commitments must be backed by credible action
UN Environment Programme, Emissions Gap Report 2019
UN Environment Programme, Facts about the climate emergency
UN Environment Programme, Nature for Climate Action
UN Environment Programme, Number of wildfires to rise by 50% by 2100 and governments are not prepared, experts warn
