Examining Human Impact On Climate
Source: Warming up to climate change: How do we know humans are causing global warming? (The Indian Express, January 9)
- Natural Cycles and Climate Variation: Earth’s climate has naturally varied over its long history. The sun’s energy does not always hit the earth with the same intensity, leading to changes in climate. Another natural influence is the ocean, which can redistribute heat globally through currents.
- Volcanoes and Climate: Volcanic eruptions can change the climate. They send dust and gases into the air, which can block sunlight and cause cooling. However, volcanoes can also warm the Earth. A past warming event happened when a volcano released a lot of CO2.
- Today’s Rapid Warming: Despite these natural factors, they are not the main cause of the current, fast climate change. NASA suggests these factors are too slow or minor to explain the quick rise in Earth’s temperatures lately.
- What is Causing the Heat: Earth is getting hotter. This is largely due to more greenhouse gases in the air. These gases trap the sun’s heat.
- The Rise of Carbon Dioxide: We burn coal, oil, and gas for energy. This sends carbon dioxide (CO2) into the air. In 150 years, CO2 levels have jumped from 280 parts per million to over 410.
- Historical Perspective: Old ice tells us CO2 hasn’t been this high for at least 800,000 years. Since the 1950s, Earth’s temperature has risen quickly.
Record-Breaking Global Temperatures in 2023
Source: Why 2023 was the warmest year ever, and what happens now (The Indian Express, January 9)
- Warmest Year on Record: The year 2023 set a new record as the hottest year. It surpassed the previous high from 2016.
- Comparing with Historical Data: 2023’s temperatures were 1.48°C above the late 19th century average. It was also 0.17°C warmer than in 2016.
- Early Predictions Confirmed: The World Meteorological Organisation forecasted 2023’s record heat in November. The forecast was based on data up to October.
Extreme Weather Events
- Heatwaves, Floods, and More: Last year saw many extreme weather events. There were heatwaves, floods, droughts, and wildfires across the globe.
- Canada’s Wildfire Season: In Canada, wildfires reached new levels of destruction. Over 45 million acres were affected from May to September.
Record-Breaking Climate Trends in 2023
Heat Records Shattered: Last year, we saw an extreme heatwave. Each day was unusually warm, breaking a historic record. Every day’s temperature was over 1 degree Celsius higher than in the 1850-1900 times. Notably, half of the year’s days were even warmer, exceeding 1.5 degrees Celsius. Twice in November, the days were over 2 degrees Celsius hotter.
Paris Agreement Thresholds: Despite these high-temperature records, we haven’t passed the critical limits from the 2015 Paris Agreement. Those limits are about long-term temperature rises over decades, not a single year.
Sea Temperatures Soar: Sea surface temperatures also hit a peak in 2023. Since mid-March, we’ve seen the highest sea temperatures on record. The Climate Reanalyzer website has shown this new trend.
Marine Heatwaves: The high sea temperatures caused many marine heatwaves. The Mediterranean, Gulf of Mexico, Caribbean, Indian Ocean, North Pacific, and North Atlantic all experienced extreme warmth.
Antarctic Sea Ice at Minimum: Antarctica’s sea ice has shrunk to its smallest extent. In September, the ice was just 16.96 million square kilometres. This is much less than the old record from 1986.
Global Warming Explained
- Increase in Greenhouse Gasses: The Earth is getting hotter. This is mostly because of more greenhouse gases in the air. These glasses, like carbon dioxide and methane, keep the Sun’s heat trapped around the Earth.
- Human Impact: Since the time when factories started, humans have burned a lot of coal, oil, and gas. This has put a lot of greenhouse gases into the air. Now the Earth is heating up very fast.
- Record Gas Levels in 2023: The amount of greenhouse gases reached new highs in 2023. Copernicus Services reported that carbon dioxide was 2.4 ppm higher than the year before. Methane increased by 11 ppb.
- El Niño’s Role: There was an El Niño last year which made things warmer. El Niño warms up ocean water in the Pacific. This leads to even more heat around the world and in the oceans.