What Is Climate Change? | United Nations

Definition of Climate Change

• Long-term shifts in temperatures and weather patterns.
• Can be natural (e.g., sun activity, volcanic eruptions) or human-induced since the 1800s.
• Main driver: burning of fossil fuels (coal, oil, gas).

Greenhouse Gas Emissions

• Burning fossil fuels generates greenhouse gases (GHGs).
• GHGs trap heat, raising Earth’s temperatures.
• Major GHGs: Carbon dioxide (CO2) and Methane (CH4).
• Sources include:
  • Gasoline (cars)
  • Coal (heating buildings)
  • Deforestation (land clearing)
  • Agriculture and fossil fuel operations.
• Key sectors contributing to GHGs:
  • Energy
  • Industry
  • Transport
  • Buildings
  • Agriculture
  • Land use.

Human Responsibility for Global Warming

• Climate scientists confirm human activities are responsible for the majority of global warming in the last 200 years.
• Current temperature increase: approximately 1.2°C since the late 1800s.
• The last decade (2011-2020) recorded the highest temperatures.
• Changes in one area of the Earth can impact other areas.

Consequences of Climate Change

• Current impacts include:
  • Intense droughts
  • Water scarcity
  • Severe fires
  • Rising sea levels
  • Flooding
  • Melting polar ice
  • Catastrophic storms
  • Declining biodiversity.

Diverse Impacts on People

• Affects health, food security, housing, safety, employment.
• Vulnerable populations (e.g., small island nations, developing countries) suffer most.
• Future displacement due to climate-related events expected to rise.

Importance of Limiting Temperature Rise

• Limiting global temperature increase to 1.5°C can avoid severe climate impacts.
• Current policies may lead to 3.1°C warming by the end of the century.
• Major emitters: China, USA, India, EU, Russia, Brazil account for over 50% of GHG emissions.
• Least developed countries contribute only 3% of global emissions.
• Greater responsibility lies with higher-emission countries.

Solutions to Climate Change

• Solutions can yield economic benefits and improve quality of life.
• Frameworks include:
  • Sustainable Development Goals
  • UN Framework Convention on Climate Change
  • Paris Agreement.
• Categories of action:
  • Cutting emissions
  • Adapting to impacts
  • Financing adjustments.
• Transition to renewable energy (solar, wind) essential.
• Need to cut emissions in half by 2030 to keep warming below 1.5°C.

Adaptation Strategies

• Protects people, infrastructure, and ecosystems.
• Must prioritize vulnerable populations.
• Early warning systems can save lives and reduce costs.

Financial Considerations

• Climate action requires significant investments.
• Inaction costs much more in the long run.
• Developed countries should assist developing nations in transition to greener economies.

Additional Resources

• Climate Dictionary: Learn terms related to climate change.
• Myths and Facts: Essential facts on climate change here.
• Causes and Effects: Learn more about fossil fuels and their impact here.
• Net Zero: Importance of achieving net zero emissions here.
• Renewable Energy: Significance in creating a safer future here.
• Climate Adaptation: Importance of adapting to climate change here.
• Climate Issues: Impacts across various sectors here.
• Women and Climate Action: Role of women in driving climate efforts here.