Global Warming

Definition

• Global warming: the long-term increase in Earth’s average temperature.

• Current warming is largely caused by human activities, especially:

  • Burning fossil fuels (coal, oil) → releases CO₂.

  • Agriculture:

    • Methane from bacteria in paddy fields (growing rice).

    • Methane from cows (through digestion / flatulence).

• Both CO₂ and CH₄ are greenhouse gases → trap heat in the atmosphere.

Scientific Process

• Peer review: scientific checking process to validate research before publication.

• Media reports are not peer-reviewed → can be oversimplified, inaccurate, or biased.

Biological Consequences

1. Loss of habitats

   • Melting ice in the Arctic → reduced habitat for polar bears and other Arctic organisms → population declines.

2. Changes in species distribution

   • Animals (e.g., birds, insects) may move northwards toward cooler climates.

   • Example: mosquitoes that carry diseases like malaria could spread into the UK.

3. Changes in migration patterns

   • Many species migrate seasonally.

   • Global warming may alter timing or routes of migration.

   • Example: swallows’ migration from the UK to Africa may shift.

4. Changes in plant growth & agriculture

   • Warmer conditions → spring plants flowering earlier in the UK.

   • New crops (e.g., grapes) may be grown in regions previously unsuitable.

   • Some regions may become too hot for traditional crops → affecting food supply.

✅ Key Points

• Human activities are driving global warming through greenhouse gas emissions.

• Biological impacts include habitat loss, species migration, disease spread, and changes in crop growth.

• Peer-reviewed research ensures scientific validity; media reports may not.