The Climate Change Portal

Average surface air temperatures from 2011 to 2020 compared to the 1951-1980 average. Source: NASA.

In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming.

Climate change is causing a range of increasing impacts on the environment. Deserts are expanding, while heat waves and wildfires are becoming more common. Amplified warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing more intense storms, droughts, and other weather extremes. Rapid environmental change in mountains, coral reefs, and the Arctic is forcing many species to relocate or become extinct. Even if efforts to minimise future warming are successful, some effects will continue for centuries. These include ocean heating, ocean acidification and sea level rise.

Climate change threatens people with increased flooding, extreme heat, increased food and water scarcity, more disease, and economic loss. Human migration and conflict can also be a result. The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. Societies and ecosystems will experience more severe risks without action to limit warming. Adapting to climate change through efforts like flood control measures or drought-resistant crops partially reduces climate change risks, although some limits to adaptation have already been reached. Poorer communities are responsible for a small share of global emissions, yet have the least ability to adapt and are most vulnerable to climate change.

Many climate change impacts are already felt at the current 1.2 °C (2.2 °F) level of warming. Additional warming will increase these impacts and can trigger tipping points, such as the melting of the Greenland ice sheet. Under the 2015 Paris Agreement, nations collectively agreed to keep warming "well under 2 °C". However, with pledges made under the Agreement, global warming would still reach about 2.7 °C (4.9 °F) by the end of the century. Limiting warming to 1.5 °C will require halving emissions by 2030 and achieving net-zero emissions by 2050.

Reducing emissions requires generating electricity from low-carbon sources rather than burning fossil fuels. This change includes phasing out coal and natural gas fired power plants, vastly increasing use of wind, solar, nuclear and other types of renewable energy, and reducing energy use. Electricity generated from non-carbon-emitting sources will need to replace fossil fuels for powering transportation, heating buildings, and operating industrial facilities. Carbon can also be removed from the atmosphere, for instance by increasing forest cover and farming with methods that capture carbon in soil. (Full article...)

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Climate change affects the physical environment, ecosystems and human societies. Changes in the climate system include an overall warming trend, more extreme weather and rising sea levels. These in turn impact nature and wildlife, as well as human settlements and societies. The effects of human-caused climate change are broad and far-reaching, especially if significant climate action is not taken. The projected and observed negative impacts of climate change are sometimes referred to as the climate crisis.

The changes in climate are not uniform across the Earth. In particular, most land areas have warmed faster than most ocean areas, and the Arctic is warming faster than most other regions. Among the effects of climate change on oceans are an increase of ocean temperatures, a rise in sea level from ocean warming and ice sheet melting, increased ocean stratification, and changes to ocean currents including a weakening of the Atlantic meridional overturning circulation. Carbon dioxide from the atmosphere is acidifiying the ocean.

Recent warming has strongly affected natural biological systems. It has degraded land by raising temperatures, drying soils and increasing wildfire risk. Species worldwide are migrating poleward to colder areas. On land, many species move to higher ground, whereas marine species seek colder water at greater depths. At 2 °C (3.6 °F) of warming, around 10% of species on land would become critically endangered. (Full article...)
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Cloud cover of the Earth
Image: Marit Jentoft-Nilsen, NASA
An image of the Earth's cloud cover, which is the amount of sky obscured by clouds, based largely on observations from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite. Clouds play multiple critical roles in the climate system. In particular, being bright objects in the visible part of sunlight, they efficiently reflect light to space and thus contribute to the cooling of the planet.


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Elizabeth Wath(y/u)ti in 2022

Elizabeth Wanjiru Wathuti (born August 1, 1995) is a Kenyan environment and climate activist and founder of the Green Generation Initiative, which nurtures young people to love nature and be environmentally conscious at a young age and has now planted 30,000 tree seedlings in Kenya.

In 2019, she was awarded the Africa Green Person of the Year Award by the Eleven Eleven Twelve Foundation and named as one of the 100 Most Influential Young Africans by the Africa Youth Awards. (Full article...)

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The following are images from various climate-related articles on Wikipedia.

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... that the research network Drawdown estimates that educating girls is the sixth most efficient action against climate change? (Pictured left: "Schoolgirls in Guinea)

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The Global Historical Climatology Network (GHCN) is one of the primary reference compilations of temperature data used for climatology, and is the foundation of the GISTEMP Temperature Record. This map shows the 7,280 fixed temperature stations in the GHCN catalog color coded by the length of the available record. Sites that are actively updated in the database (2,277) are marked as "active" and shown in large symbols, other sites are marked as "historical" and shown in small symbols. In some cases, the "historical" sites are still collecting data but due to reporting and data processing delays (of more than a decade in some cases) they do not contribute to current temperature estimates. As is evident from this plot, the most densely instrumented portion of the globe is in the United States, while Antarctica is the most sparsely instrumented land area. Parts of the Pacific and other oceans are more isolated from fixed temperature stations, but this is supplemented by volunteer observing ships that record temperature information during their normal travels. This image shows 3,832 records longer than 50 years, 1,656 records longer than 100 years, and 226 records longer than 150 years. The longest record in the collection began in Berlin in 1701 and is still collected in the present day.



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  1. ^ Bhargav, Vishal (2021-10-11). "Climate Change Is Making India's Monsoon More Erratic". Retrieved 2021-10-11.
  2. ^ Tiwari, Dr Pushp Raj; Conversation, The. "Nobel prize: Why climate modellers deserved the physics award – they've been proved right again and again". Retrieved 2021-10-11.
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