Global Warming

 

Global warming caused by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns is all part of climate change. Though there have been previous periods of climatic change, humans have had an unprecedented impact on Earth's climate system and caused global change since the mid-twentieth century. 

Emissions of greenhouse gases, of which carbon dioxide and methane account for more than 90%, are the most significant contributors to global warming. The primary source of these emissions is fossil fuel combustion for energy consumption, with contributions from agriculture, deforestation, and manufacturing. Any scientific body of national or international standing does not deny that humans are the cause of climate change. Climate feedbacks, such as the loss of sunlight-reflecting snow and ice cover, increased water vapor, and changes to land and ocean carbon sinks, can speed up or slow down temperature rise.

The rise in land temperatures is roughly twice that of the global average, resulting in desert expansion and more frequent heatwaves and wildfires. The melting of permafrost, glacial retreat, and sea ice loss in the Arctic have all been exacerbated by rising temperatures. Warmer temperatures increase evaporation rates, resulting in more severe storms and weather extremes. The relocation or extinction of many species as their environment changes, most notably in coral reefs, mountains, and the Arctic, is one of the most immediate impacts on ecosystems. Food insecurity, water scarcity, flooding, infectious diseases, extreme heat, economic losses, and displacement are all threats posed by climate change. Climate change has been dubbed the greatest threat to global health in the twenty-first century by the World Health Organization. Even if efforts to reduce future warming are successful, some effects, such as rising sea levels, rising ocean temperatures, and ocean acidification, will last for centuries. 

Many of these consequences are already being felt at the current rate of warming, which is around 1.2 degrees Celsius. In a series of reports, the Intergovernmental Panel on Climate Change (IPCC) forecasts significant increases in these impacts as global warming continues to 1.5 degrees Celsius and beyond. Increased warming also raises the risk of tipping points, which are critical thresholds that must be crossed. Mitigation and adaptation are required in the face of climate change. Mitigation entails lowering greenhouse gas emissions and removing them from the atmosphere, which can be accomplished through the development and deployment of low-carbon energy sources such as wind and solar, the phase-out of coal, increased energy efficiency, reforestation, and forest preservation. Adaptation entails making changes to one's environment, such as bettering coastal protection, disaster management, assisted colonization, and the development of more resistant crops. Adaptation alone will not be enough to prevent "severe, widespread, and irreversible" consequences.

Through mitigation efforts, nations agreed to keep warming "well below 2.0 °C" under the Paris Agreement. Despite the Agreement's pledges, global warming would still be around 2.8 degrees Celsius by the end of the century. To keep global warming to 1.5 degrees Celsius, emissions must be cut in half by 2030 and near-zero by 2050.