At its core, climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. While natural processes have always influenced the Earth's climate, the current changes are predominantly driven by human activities.
Understanding the science behind climate change, recognising its impacts, and identifying the urgent need for action are crucial steps in addressing one of the most pressing challenges of our time.
Climate change refers to long-term shifts in temperatures and weather patterns. While these changes can occur naturally, since the mid-20th century, human activities have been the primary driver of climate change. This is mainly due to the burning of fossil fuels such as coal, oil, and gas, which releases greenhouse gases (GHGs) like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) into the atmosphere. These gases trap heat, causing the Earth's average temperature to rise—a phenomenon known as global warming.
The Intergovernmental Panel on Climate Change (IPCC) has provided comprehensive assessments of climate science, indicating that the global temperature has increased by approximately 1.1°C above pre-industrial levels, with significant impacts on the environment, human health, and economies around the world.
The industrial revolution marked the beginning of significant increases in GHG emissions. As industries expanded, so did the use of fossil fuels. Deforestation for agriculture and urbanisation also played a role by reducing the number of trees that could absorb CO2. The concentration of CO2 in the atmosphere has risen by about 50% since pre-industrial times.
Methane emissions, which are more potent than CO2 but less abundant, come from sources such as agriculture (especially livestock), landfills, and the production and transport of fossil fuels. Nitrous oxide emissions mainly originate from agricultural activities, particularly the use of synthetic and organic fertilisers. These activities have significantly altered the natural GHG balance.
The impacts of climate change are already evident and widespread. Rising global temperatures contribute to more frequent and severe weather events, such as hurricanes, heatwaves, and heavy rainfall. The Arctic ice is melting at an alarming rate, leading to rising sea levels that threaten coastal communities. The past decade was the warmest on record, with increasingly severe natural disasters.
Climate change also poses significant risks to biodiversity. Many species are unable to adapt quickly enough to changing temperatures and shifting ecosystems, leading to declines in populations and disruptions in ecological balances. For example, coral reefs, which support a vast array of marine life, are experiencing widespread bleaching due to warmer ocean temperatures.
Human health is directly impacted by climate change. Increased temperatures and changing precipitation patterns can expand the range of vector-borne diseases, such as malaria and dengue fever. Additionally, extreme weather events can lead to food and water shortages, exacerbate respiratory conditions due to higher pollution levels, and increase the prevalence of heat-related illnesses and deaths.
Immediate and concerted action is required to mitigate the worst impacts of climate change. The longer we delay, the more severe and irreversible the consequences will become.
The IPCC warns that global warming must be limited to 1.5°C above pre-industrial levels to avoid catastrophic impacts. Exceeding this threshold could trigger tipping points in the climate system, leading to runaway climate change.
To combat climate change, we need to reduce GHG emissions across all sectors. This includes transitioning to renewable energy sources such as wind, solar, and hydro power. Energy efficiency must be improved in homes, businesses, and transportation systems.
Reforestation and afforestation are critical strategies for sequestering carbon dioxide. Protecting existing forests and restoring degraded lands can enhance carbon sinks and biodiversity.
Additionally, we must adapt to the changes already underway. This involves building resilient infrastructure, developing early warning systems for extreme weather events, and investing in climate-smart agriculture to ensure food security.
Climate change is a defining issue of our time, driven primarily by human activities. Its impacts are widespread, affecting every aspect of our lives. Urgent action is necessary to mitigate these effects and build a sustainable future. By reducing emissions, protecting natural ecosystems, and enhancing climate resilience, we can address the challenges posed by climate change and safeguard the planet for future generations.
