Climate change is any long-term change in average weather patterns. Climate change has happened many times in the past. Humans are to blame for the changes in global temperature and weather patterns. They are happening much faster than the natural climate variations of the past.

Climate change is linked to the emission of greenhouse gases, such as carbon dioxide and methane, and scientists have many ways to track it over time. Like the glass walls of a greenhouse, these gases trap heat from the sun's rays near Earth's surface. Major changes on a global scale can be achieved by small changes in the proportions of greenhouse gases in the air.

Greenhouse gases increase global temperatures. Climate change is called global warming because of this. Climate change is preferred by most researchers because of the variability of weather and climate across the globe. Warming global average temperatures might alter the flow of the jet stream, the major air current affecting North American weather, which could lead to seasonal periods of extreme cold in some areas.

Ellen Mosley-Thompson, a paleoclimatologist at The Ohio State University, said that there is a lot of variability from place to place on the Earth.

How do scientists know climate change is real?

The effects of global warming can be seen. The climate of the past can be found in a variety of places. Carbon dioxide trapped in bubbles inside glaciers can be used to determine atmospheric conditions in the past. They can study fossilized pollen to learn about the vegetation that used to thrive in the area. Scientists can measure tree rings to get a season-by-season record. Past precipitation patterns can be revealed by the ratios of chemical oxygen in stalagmites and stalactites.

Different types of natural records can give clues about the climate of the past. The blurrier pictures of climate dating back millions of years can be found in the ocean sediments, but they don't carry season-by-season or even year-by-year levels of detail. The oldest core drilled from the ocean is 65 million years old. The tree records are very detailed. Glaciers capture atmospheric gases in the form of air bubbles, and they also trap dust and other debris. The record can become fuzzy as the ice gets older and more compressed, but newer ice can provide a year-by-year look at what the climate was doing.

Since the beginning of the Industrial Revolution, the most recent changes in the climate have been tracked directly. In the late 1800s, record-keeping of things like land temperature began to improve, and ship captains began to keep a lot of ocean-based weather data in their logs. Satellite technology in the 1970s provided an explosion of data, covering everything from ice extent at the poles to sea surface temperature.

Cars covered in many feet of snow during a blizzard.

Overall, the Earth is warming up because of human-caused climate change. But climate change also causes seasonal periods of extreme cold. (Image credit: Shutterstock)

How is the climate changing?

The records show that the modern climate is a departure from the past.

Before the Industrial Revolution, there were about 280 carbon dioxide molecule for every million molecule in the atmosphere. The global average level of CO2 was more than 100 parts per million higher than it has been in the last 800,000 years, according to the National Oceanic and Atmospheric Administration. The last time atmospheric carbon was at its current levels was 3 million years ago.

The rate of change in the atmosphere is faster than it has been in the past. Over the past 60 years, the rate of increase has been 100 times faster than the last million years, a period in which ice expanded from the poles into the middle latitudes. The rate is increasing. In the 1960s, atmospheric carbon increased by an average of 0.6 parts per million. It rose by an average of 2.3 parts per million in the 2010s.

Global average temperatures have risen because of the heat-trapping ability of all that extra carbon. Earth's average temperature has risen by just over 2 degrees Fahrenheit (1 degree Celsius) since 1880, a measurement accurate to within a tenth of a degree Fahrenheit. The rate of global temperature increase is speeding up, as shown by the fact that two-thirds of the warming that took place since 1978 has occurred.

What are the impacts of climate change?

The warming has changed the environment. Sea ice is on the decline in the northern part of the planet. NASA says that the new normal has been record-breaking ice extent lows since 2002. The summer sea ice extent in Summer 2020 was the worst ever, with only one year on record. The first ice-free summer in the northern part of the planet is now expected in the 2060s.

Glaciers are retreating in the middle latitudes. Glacier National Park in Montana had 150 glaciers in 1850. There are 25 today. The last tropical glaciers are predicted to disappear within the next decade.

Sea levels are rising due to melting ice and the expansion of ocean waters. The global average sea level has risen over the last 120 years. In the 20th century, the rate of rise was 0.06 inches per year, but from 2006 to 2015, it was 0.14 inches per year. The sea level rise has resulted in a 900% increase in high-tide flooding in coastal areas of the United States.

Ocean water absorbs carbon dioxide from the atmosphere and creates a chemical reaction that causes ocean acidification. According to the Pacific Marine Environmental Laboratory, the global average pH of ocean surface waters has decreased by 0.11 since the Industrial Revolution began. Increasing ocean acidity makes it more difficult for corals to build their carbonate skeletons and for shelled animals such as clams and some types of plankton to survive.

The timing of spring-like weather is being affected by climate change. The earliest spring in the United States was in March of 2012 Climate models suggest that early springs could be the norm by the year 2050. Plants could leaf out early and be damaged by cold temperatures because of the late freezes. Climate models predict an increase in the number of fires due to warmer temperatures.

Kathie Dello is a state climatologist for North Carolina. Dello said that there is no way to compare different futures for Earth in the real world. The computer models have been able to predict future climate trends. The 2020 paper found that the climate model predictions published between 1970 and 2010 were accurate when compared with the actual warming that occurred after publication.

Can we reverse climate change?

A growing number of business leaders, government officials and private citizens are concerned about climate change and are proposing steps to halt and reverse the trend.

The natural processes for removing this human-caused CO2 from the atmosphere work on the timescale of hundreds of thousands to millions of years. In our own self-interests, we must act in one way or another to deal with the changes in climate we are causing.

Carbon dioxide remains in the atmosphere for hundreds of years, so if all human greenhouse gas emissions stopped immediately, Earth would likely still experience more warming. There are proposals that could theoretically reverse some of the warming by removing carbon dioxide from the atmosphere, such as carbon capture and storage. Market forces have prevented widespread adoption of carbon capture and storage.

It is not feasible to remove carbon from the atmosphere, but it is possible to stop the emission of greenhouse gases. The Paris Agreement is the most ambitious effort to slow down the warming. The nonbinding international treaty that came into effect in November 2016 aims to keep warming below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 degrees Celsius. Each of the treaty's signatories agreed to set their own voluntary emissions limits. Climate scientists said that the emissions limits that were outlined in the agreement wouldn't keep warming as low as 1.5 or even 2 degrees C, but that it would be an improvement over the business as usual scenario in which no changes are made to cut.

The United States pledged to limit greenhouse emissions to less than 28% of 2005 levels. The Paris Agreement was not honored by President Donald Trump. The formal withdrawal process from the agreement began in 2019. Joe Biden re-committed the U.S. to the Paris Agreement when he assumed the presidency in 2021. A study found that greenhouse emissions have locked in enough warming so that Earth will warm more than 3.6 F. Reducing emissions could slow the temperature rise to a more manageable rate.

Several state and local governments are trying to combat climate change. 24 states and Puerto Rico have joined the U.S. Climate Alliance, which pledges to meet the goals of the Paris Agreement regardless of politics at the federal level.

Dello said that the federal government is not the most flexible.

Additional resources

Live Science has a reference article on global warming. NASA has a view of how temperatures have changed over time. There are signs of a warming world, from sea surface temperatures to shrinking sea ice to increased water Vapor in the air.

The state of climate science is reported by the Intergovernmental Panel on Climate Change. Climate change data and projects are tracked by the World Bank.


The Intergovernmental Panel on Climate Change. The sixth assessment report has been published. The assessment report was published on Feb. 28, 2022.

The United States Geological Survey. Climate change viewer The National Climate Change Viewer can be found at

The data center has snow and ice. The news and analysis of the sea ice. was published on March 23, 2022.

The original article was written by Live Science contributor.