What You’ll Learn In This Module
- What is the Paris agreement on climate change?
- Why is a global average temperature increase of 1.5°C already a problem?
- What are the effects of climate change?
- What are the consequences of climate change on the weather?
- What are the consequences of the changing climate on the environment?
- What are the consequences of the changing climate on our societies?
- What are the consequences of the changing climate on the economy?
- What is climate adaptation? What is climate transition?
- Why is adapting to climate change difficult?
- What is dangerous climate change?
- If we continue to warm the planet, how hot will it get?
What is the Paris agreement on climate change?
The Paris Agreement was signed by 196 Parties at COP21 (21st Conference of the Parties) in December 2015. It sets out a global framework to avoid dangerous climate change by limiting global warming to “well below” 2°C above pre-industrial levels and pursuing efforts to limit it to 1.5°C.
Every five years, parties who signed the agreement should come forward with progressively more ambitious national climate goals.
At first sight, an increase in average temperatures of 1.5°C might not seem a lot, but this magnitude is already a significant problem.
The natural world is used to adapting slowly, over hundreds, thousands or even millions of years. It now faces adaption to a sharp increase in global temperatures over a relatively brief time span.
The target of 1.5°C is also an average. This means that there will be some regions of the world where the temperature increase is higher.
This is already the case in some vulnerable areas on Earth, such as Antarctica, where temperatures have already increased by 2°C.
Why is a global average temperature increase of 1.5°C already a problem?
To understand this better, look at a concrete example.
Different species of trees have different temperature, soil, light and moisture requirements. To survive and thrive, they grow in different growing zones, known as geographic ranges, across the world’s surface.
As temperatures rise, each species’ growing zone will shift, perhaps as much as 250 miles north in 20 years. But the trees can’t just pick themselves up and move. Instead, they will die off where they stand.
Their future survival depends on whether their seedlings can reestablish themselves in sufficient numbers in the new growing zone. And establish themselves fast.
With the death of these first trees, the animals, birds and insects that rely on them also lose their homes. They may weaken and die if they can’t move or if the habitats on which they depend cannot reestablish themselves in the new growing zones.
If the rate of increase in temperature was slower, then the natural world could adapt and these species would reestablish themselves.
But at this rate of change, and if the change keeps happening, the growing zones keep shifting, and the trees and their inhabitants don’t have a chance to reestablish.
This ‘displacement’ effect will affect many species and many habitats.
We rely on these communities to be healthy.
The permanent loss of just a few, or even the smallest organisms, risks destabilizing the world’s ecosystems, the networks that support the whole of life on earth.
That’s why slowing the rate of temperature rise is so important. We have to slow it down and bring it to a halt, to give these natural communities a chance to adapt and be healthy.
What are the effects of climate change?
The consequences of global climate change include changes in our weather, plus challenges to our natural environment, economies, societies and ways of living.
Changes to our weather include rising temperatures, changing precipitation patterns and more frequent extreme weather events, including intense heat waves, storms, floods and wildfires.
Changes to our natural environment include global warming, melting sea ice, sea level rise, an increase in ocean temperatures and acidity, plus a loss of plant, insect, animal and bird species (biodiversity).
Changes to our society and ways of living include the need to relocate from some areas, causing the migration of people, and adapting our homes and cities to cope with the consequences of climate change. As temperature changes get more severe, there may be possible interruptions to our food supplies, water supplies and human health.
The main changes to our economy stem from the transition away from burning fossil fuels towards other renewable energy sources. It includes the effect on economic growth, on jobs and on our energy production and use.
The consequences of global climate change are expected to worsen significantly as the temperature of the planet continues to rise.
What are the consequences of climate change on the weather?
First, the consequences of global climate change include a dramatic effect on our weather, including rising temperatures and more extreme weather events, such as:
….heat waves and droughts
While not every weather event may be caused by climate change, it has changed our baseline climate, increasing the average temperature and increased the frequency of extreme heat.
Warming up the planet causes more intense and frequent heat waves, drying out the soil and making droughts worse.
Especially in recent years, we have seen extreme heat waves in Africa, Japan and the UK.
….forest fires
As temperatures rise, so do the weather-related threats we face.
For example, in recent years there have been serious forest fires in areas usually unaffected by such events like in the artic, or in the western US and California.
The fire of 2020 in California caused 24 billion dollars of damage and 116 people died.
Areas such as Greece and Portugal have seen an increase in fire severity.
… super storms and floods
Heat is also changing our weather in other ways.
A warmer atmosphere holds more moisture.
More moisture is evaporating off the oceans and into the air, resulting in more rainfall.
Superstorms and serious flooding events have occurred.
For example in Japan, China and in Kerala in India.
This effect is more serious when it combines with increasing sea levels, since when waves break, the water levels are already higher.
We face a risk of superstorms and floods like we have never seen before.
What are the consequences of the changing climate on the environment?
Global Climate change has consequences for our environment that go far beyond just the weather. These include:
… sea level rises
As temperatures increase, water from melting ice sheets, glaciers and snow above the ground flows into the ocean.
The world’s oceans will also expand as the water gets warmer.
Both of these effects cause rising sea levels, which will affect people across the planet.
If we don’t do anything to curb changes in the earth’s climate, we may face an 80cm to 1-meter sea level rise by the end of the century.
…the ocean becoming warmer and more acidic
As we emit more carbon dioxide into the atmosphere, the ocean absorbs some of it, turning the water into a weak carbonic acid.
Also, over 90% of the heat from our warming planet had so far been stored in the oceans.
These processes are already having a devastating effect on the ocean’s wild plants and animals.
In the last 3 years, repeated heat stress has caused one-third of the world’s corals to first bleach and then die.
… a loss in biodiversity
With extreme temperatures, even creatures adapted to extreme heat may die. Just a few repeated events of extreme temperatures and deaths can cause extinction.
Losing species is irreversible. Scientists estimate that 8% of species are currently threatened with extinction solely because of climate change.
What are the consequences of the changing climate on our societies?
Climate change creates higher risk and new challenges for communities and societies across the world. These include:
…having to adapt our homes to cope with global warming
For example, coastal defences against sea level rise, storms and floods will need to be built.
…the migration of people
Accelerated sea level rise, extreme tropical storms and flooding risk displacing hundreds of thousands of people from already vulnerable coastal areas.
600 million people live in coastal areas which are less than 10 meters above sea level, such as in the South Pacific, Indonesia, Bangladesh.
In the Maldives, a sea level rise of 1 meter would flood 75% of the land’s surface. Bangladesh, Egypt, Nigeria and Thailand are also particularly vulnerable to accelerated sea level rise.
In the US, the state of Louisiana is losing land to rises in sea level at the rate of a football field (about 1 hectare) every 45 minutes.
This has made the relocation of entire communities necessary.
… a reduction in the fertility of soils and possible food insecurity
A warming planet dries out the soil, reducing its productivity.
As a result, farming may become difficult, or even impossible, in some areas.
… difficulties for our water supply
As glaciers melt, regions used to living off the meltwater from glaciers will no longer have a water supply.
The parts of the world that are likely to suffer first and most are the poorest.
…new challenges to human health
Increasing temperatures and more severe weather events may cause more disease.
Diseases may also spread to areas traditionally unaffected by them.
New diseases may arise because of new living circumstances.
Or because of other changes in the natural world.
What is climate adaptation? What is climate transition?
Climate adaptation means taking action to prepare for and adjust to future climate change.
The emissions of greenhouse gases continue to rise. Even with rapid climate action to address this, the current concentration of greenhouse gases in the atmosphere will continue to increase global temperatures.
As the global temperature changes, risks will arise that we should try to prepare for. We will need to prepare ourselves, our families, our communities and our properties.
Changes in precipitation patterns and more frequent extreme weather events like intense heat waves and superstorms may mean we need to better insulate and strengthen our properties. It may also mean that we need future mobility or emergency survival strategies.
It is very clear that building resilience for the future through adaptation is not a substitute for mitigating global climate change and reducing greenhouse gas emissions.
Climate transition is the transition towards low carbon, resource-efficient and sustainable economies.
It includes switching almost entirely to green energy, minimising the greenhouse gases produced and finding ways to reduce the existing carbon pollution, drawing down carbon from the atmosphere.
It means ensuring that we act to address and reverse global climate change as fast as possible.
It includes ensuring we use all resources efficiently and reduce our waste.
We also need to create new jobs and find private and public money to support green investments.
What are the consequences of the changing climate on the economy?
…new challenges to the economy
The effects of climate change on our economy arise largely from the necessary transition away from burning fossil fuels, towards using other, renewable energy sources. This transition will have knock-on effects on economic growth, on jobs and on our energy production and distribution.
The change in weather patterns, including warmer temperatures, extreme heat events and tropical storms, are also expected to damage infrastructure.
Future changes to the earth’s climate will disrupt normal life, exacerbating the existing challenges to some economies posed by, e.g population ageing and economic inequality. It’s likely that the vulnerable, lower-income and marginalised communities will experience the greatest impact from climate change.
Without mitigation and adaptation efforts, global climate change is expected to have large and increasing negative effects on economic growth over this century. The sooner we start these efforts, the smaller the negative effects on our economies.
Why is adapting to climate change difficult?
Wildlife and people are used to the climates of the place where they live.
Each society has a coping range, a range of weather within which it knows how to live.
Climate change is pushing societies beyond, sometimes far beyond, the climates of the past and making them live in new climates, to which they may not be adapted.
People may have to move from the areas where they live.
Infrastructures such as sea defences and roads may need to be adapted.
Homes may have to be repaired or rebuilt.
Millions of people have and will continue to need humanitarian aid as a result of climate change.
As temperatures increase, we will need to build flexible and resilient societies that can adapt to a changing future.
What is dangerous climate change?
The level of temperature increase considered dangerous depends on where you live.
If you live on a small island, a low-lying country or in a coastal region, any sea level rise may be serious.
It can have a potentially dangerous impact because it directly results in a loss of land through flooding.
But many scientists and organizations, including the IPCC, believe that a global temperature rise of 2 degrees centigrade is the level at which everyone experiences the negative consequences of climate change.
At this level, the number of people at risk from water shortages, hunger, malaria and flooding increases rapidly.
There may also be more extreme dangers, linked to irreversible changes that are called ‘tipping points’.
Once a tipping point is crossed, change continues, since it’s impossible to undo what has changed.
Examples of tipping points can include irreversible ice meltdowns or major changes in ecosystems that tip the environment into another state.
The science is clear that urgent action is needed to stop climate change.
What we decide to do over the next 10 years will profoundly affect our future.
If we continue to warm the planet, how hot will it get?
If we continue to release greenhouse gases such as carbon dioxide into the atmosphere, temperatures will keep rising.
But do we know by how much?
Using climate models, scientists expect global average temperatures to increase by 1.5 degrees centigrade between 2040 and 2050.
They expect an increase of 2 degrees shortly after that.
It’s difficult to predict how climate systems might behave and it becomes more difficult as we look further in the future.
Existing climate models suggest increases of between 3 and 6 degrees into the next century
3 degrees is already considered extremely serious.
Are we sure that it’s greenhouse gases that are causing global warming? How long do they remain in the atmosphere? Get clear on the role of greenhouses gasses in climate change.