Note4Students
From UPSC perspective, the following things are important :
Prelims level: 1.5 degree Celsius Threshold
Mains level: Read the attached story
Introduction
- The year 2023 witnessed alarming signs of climate change, from record-breaking summer temperatures to shrinking Antarctic sea ice and extreme weather events across the globe.
- Despite the overwhelming scientific consensus on climate change, there remains confusion and misinformation on this critical issue.
Is the Earth Becoming Warmer?
- Temperature Measurement: Temperature measurements since the late 1880s show global warming trends. Satellite data confirms an increase of at least 1.1 degrees Celsius since 1880.
- Indirect Verification: Analyzing natural indicators like tree rings and ice cores. Observing effects such as warming oceans, shrinking ice cover, and rising sea levels. Multiple monitoring systems enhance confidence in global-scale warming.
- Acceleration of Warming: Recent decades witness unprecedented rapid warming. The majority of warming observed since 1975. 2022 marked the 46th consecutive year of temperatures above the 20th-century average.
Role of Human Activities
- Natural Factors: Throughout Earth’s history, natural factors like solar variations and volcanic activity influenced climate.
- Current Acceleration: However, natural factors exert too little influence and operate too slowly to account for recent rapid warming, as acknowledged by NASA.
- Greenhouse Gases: The primary driver of global warming is the increasing concentration of greenhouse gases, particularly carbon dioxide (CO2), methane (CH4), and water vapor.
- Human Influence: Since the Industrial Revolution, human activities, especially the burning of fossil fuels, have released substantial greenhouse gases into the atmosphere.
- Unprecedented Change: Changes that would typically occur over hundreds of thousands of years are now happening within decades.
Overwhelming Evidence
- Scientific Consensus: The Intergovernmental Panel on Climate Change (IPCC) has stated that “human influence on the climate system is clear and growing.”
- Unprecedented Warmth: 2022 marked the 46th consecutive year with global temperatures exceeding the 20th-century average, with the last nine years ranking among the warmest.
1.5 Degree Celsius Threshold
- Paris Agreement: 195 countries pledge to limit warming to “well below 2 degrees Celsius” and aim to limit the increase to 1.5 degrees Celsius.
- Baseline Year: Pre-industrial levels based on measurements from 1850 to 1900, providing a reliable historical reference.
- Reason for 1.5 Degrees: Scientific consensus: 1.5 degrees is a defense line against severe climate impacts. It avoids extreme and irreversible consequences associated with 2 degrees warming.
- Continuous Improvement: Lowering the target reduces climate risks further. Science supports aiming for the lowest possible temperature increase.
Consequences of Breaching the Threshold
- Increased Extreme Weather: More frequent and intense heavy precipitation. Elevated drought intensity and frequency in some regions.
- Warmer Oceans: Higher number of strong hurricanes with rapid strengthening.
- Intensified Wildfires: Longer-lasting and more intense wildfires.
- Rapid Sea Ice Melt: Accelerated sea-level rise.
- Emerging Consequences: Many of these impacts are already underway. Breaching the threshold exacerbates these effects.
How Close Are We to Breaching the Threshold?
- WMO Warning: World Meteorological Organisation (WMO) warns of a 66% chance of crossing the 1.5-degree limit between 2023 and 2027.
- Hottest Year: 2023 declared the hottest year on record, 1.48 degrees Celsius warmer than pre-industrial levels.
- Daily Fluctuations: Daily temperatures occasionally exceed 1.5 degrees Celsius, but long-term trends are the focus.
Conclusion
- The evidence of climate change and global warming is undeniable.
- Human activities, primarily the release of greenhouse gases, are driving these changes at an unprecedented rate.
- Understanding the science behind climate change is crucial in addressing this real global crisis.
Get an IAS/IPS ranker as your 1: 1 personal mentor for UPSC 2024