Global Warming
Global warming refers to the long-term rise in Earth’s average surface temperature, including increased temperatures of oceans and the troposphere. According to the UN Framework Convention on Climate Change, the primary cause of global climate change is human-caused greenhouse gas emissions.
Without the natural greenhouse effect, Earth’s average surface temperature would be –19 °C instead of today’s 14 °C.
Natural Global Phenomena
- Solar cycles: Variations in solar irradiance, sunspots, Earth’s orbital elements, plate tectonics, and volcanic activity.
- Volcanic eruptions: Emit CO₂ and other gases. While CO₂ warms, ash and aerosols typically cool by blocking sunlight.
- Milanković cycles: Changes to Earth’s tilt and orbit over thousands of years affecting climate patterns.
- Ocean currents: Systems like El Niño and La Niña periodically influence global temperatures.
- Any change in greenhouse gas levels alters Earth’s energy balance—leading to extreme weather, melting ice sheets and glaciers, sea-level rise, shifts in precipitation and wind patterns, and threats to ecosystems.
Human Activities Driving Global Warming
Greenhouse Gas Emissions
- CO₂ emissions from burning fossil fuels in energy production, transportation, etc.
- Methane (CH₄) from agriculture and livestock.
- Nitrous oxide (N₂O) from fertilizer use.
- Fluorinated gases (F-gases) from industrial processes and refrigeration.
Overconsumption
- Industrial manufacturing and shipping release vast CO₂ and pollutants.
- Cars powered by fossil fuels contribute significantly.
- Plastic production and incineration: 400 million tonnes of plastic produced yearly emit ~850 Mt CO₂ (~2 % of global emissions). Burning one tonne of plastic yields ~2.9 tonnes of CO₂, also releasing toxins.
Plastic pollution harms marine ecosystems; microplastics affect plankton—crucial for carbon capture. Only 9 % of plastic is recycled globally; the rest is landfilled, incinerated, or littered. Chemical recycling offers promising solutions.
Alternative Theories
- Cosmic rays may affect cloud formation and Earth’s energy balance.
- Skeptics argue that modern climate models over-rely on assumptions and overestimate human impact.
Future Projections
- The IPCC forecasts a 2–4 °C temperature rise by 2100, alongside rising sea levels endangering coastal cities and islands, extreme heatwaves, heavy rainfall, droughts, hurricanes, habitat shifts, species extinctions, falling agricultural yields, water shortages, and increased migration with socioeconomic consequences.
Technological Responses
- Carbon capture and storage (CCS) with renewable energy:
- Petra Nova (USA) and Sleipner (Norway) capture and store large volumes of CO₂ in deep geological formations.
- BECCS (bioenergy with CCS):
- The Drax power station (UK) uses BECCS to generate energy while capturing emitted CO₂.
- Natural carbon sinks:
- Forest planting and protection (e.g., India’s Green India Mission, Africa’s Great Green Wall), regenerative agriculture, composting, agroforestry, and ocean-based carbon sequestration.
- Emerging technologies:
- Algae farms (photosynthetic CO₂ capture), “blue carbon” ecosystems (mangroves, seagrasses, salt marshes), CO₂-infused building materials (e.g., carbon-cured concrete), synthetic fuels (e.g., methanol, synthetic kerosene), and carbonation in beverage production.
Critical Timeframes
- The Paris Agreement aims to keep global warming below 1.5 °C above pre-industrial levels.
- According to the IPCC, achieving this requires a 50 % emissions cut by 2030 and reaching net-zero by 2050—we have less than seven years at current rates.
- Climate systems (e.g., Greenland ice sheet, Amazon rainforest) risk irreversible tipping points within 10–20 years if warming reaches 2 °C.
If We Run Out of Time (2030–2050)
- Immediate impacts: worsening food and water shortages, especially in the poorest countries, more hurricanes, floods, droughts, heatwaves, sea-level rise, and natural disasters.
- Long-term impacts (post-2100):
- A 4 °C rise could lift sea levels by up to 2 m, flooding coastal cities and islands, destroy coral reefs, disrupt food supplies, and trigger mass migration, resource conflicts, and political instability.
Humanity must make decisions by 2030 to drastically reduce greenhouse gas emissions and adopt sustainable technologies. Through innovation, renewable energy, energy efficiency, and global cooperation, we still have a chance to limit warming and safeguard our future.
Further Reading
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Compiled from Wikipedia, processed and refined using OpenAI’s ChatGPT.