What are the effects of climate change?

Global sea levels are on the rise because of melting ice caps and expanding seawater as it warms. Levels have increased about 24 centimetres since reliable records began almost a century and a half ago. But some scientific models suggest that by 2100, sea levels could reach 2.2 meters on average if we continue carbon emissions at our current rate. Rising seas dramatically increase the odds of damaging coastal floods from storm surges.

Another consequence of climate change is wide variations in weather patterns. Scientific studies indicate that extreme weather events such as heatwaves and violent storms are likely to become more frequent or more intense, leading to severe flooding, droughts, forest fires and widespread storm damage.

The environmental changes being driven by climate change such as desertification are also disturbing natural habitats and species. There are signs that rising temperatures are affecting biodiversity, while changing rainfall patterns, extreme weather events and ocean acidification are putting pressure on species already at threat.

The effects of human-induced climate change continue to drive the displacement and migration of millions of people across the world. They are being forced from their homes as natural resources such as drinking water become even scarcer, and as crops and livestock struggle to grow and survive in conditions that are too hot and dry or too cold and wet, threatening people’s livelihoods. In such situations, climate change can exacerbate existing tensions and add to the potential for conflict.

According to the UNHCR, an annual average of 21.5 million people have been forcibly displaced by weather-related events since 2008. These numbers are expected to rise dramatically in the coming decades with forecasts suggesting that 1.2 billion people could be displaced globally by 2050 due to climate change and natural disasters.

The increasing intensity and frequency of extreme weather events, such as violent storms, cyclones, prolonged droughts and rising sea levels can result in massive economic losses for communities and whole countries. 

After a climate-related disaster strikes, there are direct costs associated with rebuilding damaged or destroyed housing and infrastructure, and the decline in value of crops or livestock that have been lost.

But there are other indirect costs. Countries may experience a slowdown in economic activity because of an interruption in business, and disruption to transport networks and supply chains. There are also macroeconomic impacts, such as increases in government debt, negative effects on stock markets and a decline in GDP.

Climate change’s impact on agriculture is already being felt across the world, with serious implications for the rural poor and global food security.

Sudden variations in weather patterns, an increase in invasive crops and pests, and soaring energy costs can badly affect agricultural productivity. Water required for food production is becoming scarcer in some places because of drought. All of these factors can contribute to a rise in food prices globally, making access to food more difficult for more and more people.

The UN warns that the effects of climate change – along with conflict and poverty - could see food prices jump by 8.5% by 2027.

From the spread of infectious diseases because of flooding or warmer climates, to the disruption of food systems by extreme weather, climate change is significantly impacting human health.

Sudden losses of food production and lack of access to food are linked to increased rates of undernutrition in many of the world’s poorest communities. A 2021 UN report showed that as many as 828 million people — or 9.8 percent of the global population — are hungry, up by 150 million from 2019.

Climate change is also a major factor in the emergence of diseases in new parts of the world as they expand their range. Extreme weather events can also result in ideal conditions for infectious water-borne diseases, like cholera, to spread.

Climate change affects all of us, but some communities are impacted more than others. While high-income countries are responsible for most greenhouse gas emissions, it is low-income countries that bear the brunt.

In many of the countries where Concern works, such as Bangladesh, Pakistan, Somalia and Malawi, the effects of climate change and extreme poverty reinforce one another.

And while global leaders at COP27 recently agreed to establish a ‘loss and damage’ fund to support the response of the world’s poorest countries to the climate crisis, it is important to consider how wider efforts to reduce poverty and inequality could also reduce the vulnerability of more at-risk communities to the devastating effects of climate change.