- Is global warming still happening? -
-What is global warming?
-- Global warming is the trend of Earth - {`'`} - s temperature rising at an unprecedented rate starting in the mid - 20th century. - -
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- Though gradual changes to Earth
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- s climate have happened in the past, this latest trend has been
- primarily caused by the release of carbon dioxide (
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- Since the mid 1950s, Earth - {`'`}s temperature has had a clear positive trend (see fig. 1). -
-- The amount Earth has warmed is measured against the average - pre-industrial global temperature. As of - {` `} - {latestTempYear}, Earth - {`'`}s temperature is approximately - {` `} - {currentTemp} - °C above pre-industrial levels. - - {` `} - If the planet - {`'`}s temperature continues to rise, we can expect many - environmental and societal impacts, the most significant of which - we will explain here. -
-- In late 2015, 184 nations were party to the Paris Climate Accord, - a UN agreement dealing with reducing greenhouse gas emissions in - an effort to mitigate global warming. The stated goal of the - agreement is to limit the average global temperature to 1.5°C - above pre-industrial levels. - -
-- In 2018, the UN released a report detailing the potential impacts - of human-induced climate change and possible preventative - measures. Its key finding was that staying below the 1.5°C target - is possible, but would require - {` `} - {`"`} - rapid, far-reaching, and unprecedented changes in all aspects of - society - {`"`} - . - - {` `} - Human carbon emissions would need to decrease by 45% from 2010 - levels by 2030, and reach net zero by 2050. - -
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- The primary cause of global warming is the human emission of
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- Since
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Effects of global warming
-- Global warming will impact a wide range of issues including - health, livelihoods, food security, water supply, human security, - and economic growth. - - {` `} - The severity of these impacts is determined by how hot Earth gets; - reaching 2°C above the pre-industrial average would put millions - more people at risk than if global warming was limited to 1.5°C. - - {` `} - Generally speaking, - {`"`} - countries in the tropics and Southern Hemisphere subtropics are - projected to experience the largest impacts on economic growth. - {`"`} - -
-- The UN projects more frequent weather extremes (both heavy rain - and drought) and temperature extremes due to global warming. - - {` `} - The most immediate risk to the environment is the dying-off of - coral reefs- a process that has already started on a large scale - (see fig. 3). -
-- The changing climate is likely to increase the prevalence of - disease. Global increases in temperature are estimated to alter - the distribution of insects that are known vectors for pathogens, - such as mosquitos. - - {` `} - Studies in China show that increasing temperatures positively - affect the viability of disease transfer by decreasing the viral - incubation time in vectors -- leading to increased infection - rates. - - The World Health Organization estimated that climate change has - been responsible for 3% of diarrhoea, 3% of malaria, and 3.8% of - dengue fever deaths worldwide in 2004. Total attributable - mortality was about 0.2% of deaths in 2004; of these, 85% were - child deaths. - -
-- Global biodiversity comes under major threat from climate change - as changing environments increase extinction pressure on species. - A review in 2013 reveals that changing environments may lead to - the extinction of thousands of species within the next 100 years. - The proximate causes of such extinctions include biotic and - abiotic factors, such as limited physiological tolerance to high - temperatures and changing species interactions. - -
-- As the threat to biodiversity looms, so does the increase of - zoonotic disease across the globe. A greater biodiversity gives - pathogens less room to dominate and spread, and as humans exploit - and degrade these vital ecosystems, conditions become more - favorable to these hosts, vectors, and pathogens. - - {` `} - With the rise of COVID-19 and its effects being heavily felt - world-wide, it is unmistakably clear that the spread of these - zoonotic diseases is a major outcome of our overexploitation of - natural resources and vital habitats. As demand for meat and land - increase, massive deforestation has significantly raised human - contact with wild animals and their body fluids which may be - vectors for pathogens. - -
-- Other already-visible impacts of global warming include worldwide - glacier and sea ice melting, which contributes to sea level rise. - - {` `} - However, thermal expansion is a larger component in this, - contributing 70-75% of sea level rise. - - {` `} - Some regions have experienced severe drought, leading to - food-and-water shortages as well as wildfires. - -
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