Global warming

Definition

Global warming refers to the long-term increase in Earth's average surface temperature due to human activities, primarily the emission of greenhouse gases such as carbon dioxide and methane. This rise in temperature is linked to various atmospheric changes and climate feedback mechanisms that can amplify or mitigate its effects on ecosystems and weather patterns.

5 Must Know Facts For Your Next Test

1. The Intergovernmental Panel on Climate Change (IPCC) reports that global temperatures have increased by about 1.1°C since the late 19th century, with significant contributions from human-induced greenhouse gas emissions.
2. Feedback loops can accelerate global warming; for instance, as temperatures rise, permafrost melts, releasing stored carbon and methane into the atmosphere, further enhancing warming.
3. Global warming leads to more extreme weather events, such as heatwaves, heavy rainfall, and droughts, impacting agriculture, water supply, and natural ecosystems.
4. Ocean acidification is a direct consequence of increased atmospheric CO2 levels, threatening marine life and disrupting oceanic food webs.
5. Mitigating global warming requires international cooperation to reduce emissions through renewable energy sources, carbon capture technologies, and sustainable practices.

Review Questions

• How do climate feedbacks influence the rate of global warming?
  • Climate feedbacks play a crucial role in influencing global warming by either enhancing or reducing its effects. Positive feedback mechanisms, such as the melting of polar ice, lead to decreased albedo effect and increased absorption of sunlight, thus accelerating temperature rises. Conversely, negative feedbacks could potentially moderate warming effects, but the predominance of positive feedback loops suggests that global warming is likely to continue escalating unless significant measures are taken to reduce greenhouse gas emissions.
• What role do greenhouse gases play in global warming and how does their concentration affect climate systems?
  • Greenhouse gases like carbon dioxide and methane are essential in regulating Earth's temperature by trapping heat in the atmosphere. As human activities increase the concentration of these gases through fossil fuel burning and deforestation, they enhance the greenhouse effect. This leads to higher average temperatures and disrupts climate systems by causing shifts in weather patterns, increasing the frequency of extreme weather events, and altering precipitation regimes.
• Evaluate the potential long-term impacts of global warming on ecosystems and human societies.
  • The long-term impacts of global warming on ecosystems and human societies are profound and multifaceted. Ecosystems may experience shifts in biodiversity as species adapt or migrate in response to changing temperatures and habitats. Human societies face challenges such as food insecurity due to altered agricultural productivity, increased health risks from heatwaves and disease vectors, and socioeconomic disruptions from natural disasters. Effective adaptation strategies will be critical for mitigating these impacts while addressing underlying causes of greenhouse gas emissions.

Related terms

greenhouse gases: Gases such as carbon dioxide, methane, and nitrous oxide that trap heat in the atmosphere, contributing to the greenhouse effect and global warming.

climate feedbacks: Processes that can either amplify or diminish the effects of climate change; for example, melting ice reduces reflectivity, leading to further warming.

carbon cycle: The series of processes by which carbon compounds are interconverted in the environment, including absorption by plants and release through respiration or combustion.