When it comes to defining climate, it is often said that “climate is what you expect; weather is what you get.” That is to say; climate is the statistically-averaged behavior of the weather. In reality, it is a bit more complicated than that, as climate involves not just the atmosphere, but the behavior of the entire climate system—the complex system defined by the coupling of the atmosphere, oceans, ice sheets, and biosphere. Weather is the current conditions of the atmosphere for a specific location and time.
Having defined climate, we can begin to define what climate change means. While the notion of climate is based on some statistical average of the behavior of the atmosphere and ocean, this typical behavior can change over time. That is to say, what you “expect” of the weather is not always the same. For example, during El Niño years, we expect it to be wetter in the winter in California and snowier in the southeastern U.S., and we expect fewer tropical storms to form in the Atlantic during the hurricane season. So, the climate itself varies over time.
If the climate is always changing, then is climate change by definition always occurring? Yes and No. A hundred million years ago, during the early part of the Cretaceous period, dinosaurs roamed a world that was almost certainly warmer than today. The geological evidence suggests, for example, that there was no ice even at the North and South poles. Climate change is a naturally occurring process of the planet, following a variety of different cycles. Something else is occurring that is causing the planet to warm
So, the significant climate changes in Earth’s geologic past were closely tied to changes in the greenhouse effect. Those changes were natural. The changes in greenhouse gas concentrations that scientists talk about today are, however, not natural. They are due to human activity.
The scientific consensus demonstrates that climate change in the 21st century is necessarily a human problem. People are causing climate change through their everyday actions and the socioeconomic forces underlying those actions. At the same time, people are feeling the consequences of climate change through various impacts on things they value, and through the responses, they are making to address climate change.
Climate is the average of weather (typically precipitation and temperature) in a particular location over a long period, usually for at least 30 years. A location’s climate can be described by its air temperature, humidity, wind speed and direction, and the type, quantity, and frequency of precipitation. Climate can change, but only over long periods. The climate of a region depends on its position relative to many things.
The scientific consensus is clear, in that 97 percent of all scientists who directly study climates and climate change believe that the current warming of the planet is anthropogenic (human) in nature. Moreover, all of the scientific evidence and planetaryvital signs indicate that more greenhouse gases are trapping Earth’s heat, causing average annual global temperatures to rise. While temperatures have risen since the end of the Pleistocene, 10,000 years ago, this rate of increase has been more rapid in the past century and has risen even faster since 1990. The nine warmest years on record have all occurred since 1998, andNASA and NOAA reported in 2019 that the year 2018 was the fourth warmest ever recorded on the planet.The 2010-2020 is predicted to be the warmest decade yet, followed by 2000-2010.
The United States has long been the largest emitter of greenhouse gases, with about 20 percent of total emissions. As a result of China’s rapid economic growth, its emissions surpassed those of the United States in 2008. However, it is also essential to keep in mind that the United States has only about one-fifth the population of China. What is the significance of this? The average United States citizen produces far more greenhouse gases than the average Chinese person.
Climate change can be a naturally occurring process and has created environments much warmer than today, such as the early Cretaceous period. During this time, life thrived even in regions, such as the interior of Antarctica, that is uninhabitable today.
One misconception is that the threat of climate change has to do with the absolute warmth of the Earth. That is not, in fact, the case. It is, instead, the rate of change that has scientists concerned. Living things, including humans, can quickly adapt to substantial changes in climate as long as the changes take place slowly, over many thousands of years or longer. However, adapting to changes that are taking place on timescales of decades is far more challenging. However, the planet is warming at such a rate that most species, especially mammals, will struggle to adapt and evolve quickly enough to the coming warmer climates.
The natural increase in atmospheric carbon dioxide that led to the thaw after the last Ice Age was an increase from 180 parts per million (ppm) to about 280 ppm. This was a smaller increase than the present-time increase due to human activities, such as fossil fuel burning, which thus far have raised CO2 levels from the pre-industrial value of 280 ppm to a current level of over 410 ppm – a level which is increasing by 2 ppm every year. So, arguably, if the dawn of industrialization had occurred 18,000 years ago, we may very likely have sent the climate from an ice age into the modern pre-industrial state.
How long it would have taken to melt all of the ice is not precisely known, but it is conceivable it could have happened over a period as short as two centuries. The area ultimately flooded would be considerably more significant than that currently projected to flood due to the human-caused elevation of carbon dioxide that has taken place so far. Below is a video from Science Insider on what the planet would like today if all the glaciers melted.
By some measures, human interference with the climate back then, had it been possible, would have been even more disruptive than the current interference with our climate. That interference would merely be raising global mean temperatures from those of the last Ice Age to those that prevailed in modern times before industrialization. What this thought experiment tells us is that the issue is not whether some particular climate is objectively “optimal.” The issue is that human civilization, natural ecosystems, and our environment are heavily adapted to a particular climate — in our case, the current climate. Rapid departures from that climate would likely exceed the adaptive capacity that we and other living things possess, and cause significant consequent disruption in our world.
The amount of carbon dioxide levels will continue to rise in the decades to come. However, the impacts will not be evenly distributed across the planet. Some of those impacts will depend on environmental and climate factors; other impacts will be dependent on whether the countries are developed or developing. Scientists use sophisticated computer models to predict the effects of greenhouse gas increases on climate systems globally for specific regions of the world.
If nothing is done to control greenhouse gas emissions, and they continue to increase at current rates, the surface temperature of the Earth can be expected to increase between 0.5 degrees C and 2.0 degrees C (0.9 degrees F and 3.6 degrees F) by 2050 and between 2 degrees and 4.5 degrees C (3.5 degrees and 8 degrees F) by 2100, with carbon dioxide levels over 800 parts per million (ppm). On the other hand, if severe limits on carbon dioxide emissions begin soon, temperatures could rise less than 1.1 degrees C (2 degrees F) by 2100.
Whatever the temperature increase, it will not be uniform around the globe. A rise of 2.8 degrees C (5 degrees F) would result in 0.6 degrees to 1.2 degrees C (1 degree to 2 degrees F) at the equator, but up to 6.7 degrees C (12 degrees F) at the poles. So far, global warming has affected the North Pole more than the South Pole, but temperatures are still increasing at Antarctica.
There are a variety of possible and likely effects of climate change on human and natural environments. NASA has tried to list some of those potential effects and can be found here. NASA also has a website called the Climate Time Machine, to help visualize Earth’s key climate indicators and how they are changing over time.
Species Mating and Migration
The timing of events for species is changing. Mating and migrations take place earlier in the spring months, and species that are more mobile are migrating uphill. Some regions that were already marginal for agriculture are no longer farmable because they have become too warm or dry.
Coral Reef Bleaching
Melting Snowpack and Glaciers
Decreased snowpacks, shrinking glaciers, and the earlier arrival of spring will all lessen the amount of water available in some regions of the world, including the western United States and much of Asia. Ice will continue to melt, and sea level is predicted to rise 18 to 97 cm (7 to 38 inches) by 2100. An increase this large will gradually flood coastal regions where about one-third of the world’s population lives, forcing millions of people to move inland.
Glaciers are melting, and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use?
Oceans and Rising Sea Levels
As greenhouse gases increase, changes will be more extreme. Oceans will become slightly more acidic, making it more difficult for creatures with carbonate shells to grow, and that includes coral reefs. A study monitoring ocean acidity in the Pacific Northwest found ocean acidity increasing ten times faster than expected and 10 percent to 20 percent of shellfish (mussels) being replaced by acid-tolerant algae.
Plant and animal species seeking cooler temperatures will need to move poleward 100 to 150 km (60 to 90 miles) or upward 150 m (500 feet) for each 1.0 degrees C (8 degrees F) rise in global temperature. There will be a tremendous loss of biodiversity because forest species cannot migrate that rapidly. Biologists have already documented the extinction of high-altitude species that have nowhere higher to go.
One may notice that the numerical predictions above contain wide ranges. Sea level, for example, is expected to rise somewhere between 18 and 97 centimeters by 2100. The reason for this uncertainty is in part because scientists cannot predict precisely how the Earth will respond to increased levels of greenhouses gases. How quickly greenhouse gases continue to build up in the atmosphere depends in part on the choices we make.
Weather will become more extreme with heatwaves and droughts. Some modelers predict that the Midwestern United States will become too dry to support agriculture and that Canada will become the new breadbasket. In all, about 10% to 50% of current cropland worldwide may become unusable if CO2 doubles. There are global monitoring systems to help monitor potential droughts that could turn into famines if they occur in politically and socially unstable regions of the world, and if appropriate action is not taken in time. One example is the Famine Early Warning System Network (FEWS NET), which is a network of social and environmental scientists using geospatial technology to monitor these situations. However, even with proper monitoring, if nations do not act, catastrophes can occur like in Somalia from 2010-2012.
Although scientists do not all agree, hurricanes are likely to become more severe and possibly more frequent. Tropical and subtropical insects will expand their ranges, resulting in the spread of tropical diseases such as malaria, encephalitis, yellow fever, and dengue fever.
An important question people ask is this: Are the increases in global temperature natural? In other words, can natural variations in temperature account for the increase in temperature that we see? The scientific data shows no, natural variations cannot explain the dramatic increase in global temperatures. Changes in the Sun’s irradiance, El Niño and La Niña cycles, natural changes in greenhouse gas, plate tectonics, and the Milankovitch Cycles cannot account for the increase in temperature that has already happened in the past decades.
In December 2013 and April 2014, the Intergovernmental Panel on Climate Change (IPCC) released a series of damaging reports on not only the current scientific knowledge of climate change but also on the vulnerability and impacts to humans and ecosystems. Below are two videos detailing the physical science of climate change and the risks and impacts on the planet.
Climate change can also be caused by human activities, such as the burning of fossil fuels and the conversion of land for forestry and agriculture. Since the beginning of the Industrial Revolution, these human influences on the climate system have increased substantially.
The IPCC report 2022 warned that the world is set to reach the 1.5ºC level within the next two decades and said that only the most drastic cuts in carbon emissions from now would help prevent an environmental disaster.What is climate change introduction? ›
Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle. But since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas.Is climate change anthropogenic? ›
Anthropogenic causes of climate change
Humans—more specifically, the greenhouse gas (GHG) emissions that human activity generates—are the leading cause of the earth's rapidly changing climate today. Greenhouse gases play an important role in keeping the planet warm enough to inhabit.
Those changes which are the result of human activities are known as anthropogenic changes. They affect the ecosystem by habitat destruction. Industrialization, pollution, deforestation, urbanization, building dams, etc., are some of the examples of anthropogenic changes that affect the ecosystem.What are the 3 main anthropogenic sources? ›
What are the three main anthropogenic sources of gaseous air pollutants in the US? gaseous air pollutants in the US are industry, transportation, and energy production.Which country is the most affected by climate change 2022? ›
- JAPAN (Climate Risk Index: 5.5) ...
- PHILIPPINES (Climate Risk Index: 11.17) ...
- GERMANY (Climate Risk Index: 13.83) ...
- MADAGASCAR (Climate Risk Index: 15.83) ...
- INDIA (Climate Risk Index: 18.17) ...
- SRI LANKA (Climate Risk Index: 19)
- Introduction. ...
- Impacts of climate change are occurring now. ...
- Key impacts and the most vulnerable places can now be identified. ...
- There are very likely to be impacts due to altered frequencies and intensities of extreme weather, climate and sea-level events.
The IPCC estimates that in the next decade alone, climate change will drive 32-132 million more people into extreme poverty. Global warming will jeopardize food security, as well as increase the incidence of heat-related mortality, heart disease and mental health challenges.Why is climate change important short answer? ›
Climate change won't just impact forest, or coral reefs, or even people in far-off countries – it will affect all of us. From more extreme weather to increasing food prices, to recreation and decreased opportunities to appreciate the natural world, people everywhere will feel its effects.
Scientists use the word “anthropogenic” in referring to environmental change caused or influenced by people, either directly or indirectly.What are anthropogenic effects? ›
Anthropogenic effects, processes, objects, or materials are those that are derived from human activities, as opposed to those occurring in natural environments without human influences.What is an example of an anthropogenic? ›
Anthropogenic process types are defined as being intentional, non-malicious human activities. Examples include groundwater abstraction, subsurface mining, vegetation removal, chemical explosions and infrastructure (loading).What are the harmful impacts of anthropogenic climate change? ›
Some noticeable evidence occurring from anthropogenic climate change is the overall sea level rise, temperature rise, melting ice sheets and glaciers, increased extreme events such as hurricanes getting stronger and ocean acidification.What are the impact of anthropogenic on the environment? ›
Anthropogenic activities and natural processes pollute soil and aquatic environments with high quantity of organic pollutants or substances such as pesticides, solvents, halogenated compounds, petroleum hydrocarbons, and phthalate esters.How does anthropogenic affect the environment? ›
Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water.What are 4 anthropogenic threats? ›
Human impact on biodiversity, direct or indirect, involves four basic factors: (1) overexploitation of natural resources; (2) habitat modification, conversion, and fragmentation; (3) the introduction of exotic (nonnative) species; and (4) pollution.What are the five anthropogenic activities? ›
Some human activities that cause damage (either directly or indirectly) to the environment on a global scale include population growth, overconsumption, overexploitation, pollution, and deforestation.What causes anthropogenic factors? ›
Human population growth and economic activity convert vast natural areas for settlement, agriculture and forestry. This produces ecological effects of habitat destruction, degradation, and fragmentation which are among the most important causes of species declines and extinctions.
- Put a price on carbon.
- End fossil fuel subsidies.
- Build low-carbon, resilient cities.
- Increase energy efficiency and use of renewable energy.
- Implement climate-smart agriculture and nurture forest landscapes.
- Keep fossil fuels in the ground. ...
- Invest in renewable energy. ...
- Switch to sustainable transport. ...
- Help us keep our homes cosy. ...
- Improve farming and encourage vegan diets. ...
- Restore nature to absorb more carbon. ...
- Protect forests like the Amazon. ...
- Protect the oceans.
- Make your voice heard by those in power. ...
- Eat less meat and dairy. ...
- Cut back on flying. ...
- Leave the car at home. ...
- Reduce your energy use, and bills. ...
- Respect and protect green spaces. ...
- Invest your money responsibly. ...
- Cut consumption – and waste.
The wildlife we love and their habitat will be destroyed, leading to mass species extinction. Superstorms, drought, and heat waves would become increasingly common and more extreme, leading to major health crises and illness. Agricultural production would plummet, likely leading to global food shortages and famine.How is climate change affecting the world 2022? ›
As the atmosphere becomes warmer, it holds more water, which, on average, makes wet seasons and events wetter. With further emissions and rising temperatures, heavy rainfall episodes will become more common. In June and July 2022, Europe was affected by two extreme heatwaves and drought.Who is most at risk of climate change? ›
However, certain groups are at more risk than others due to both climate and non-climate factors. For example, people living on floodplains, coastlines, or in areas prone to severe storms are more vulnerable to extreme weather. Those living in poverty may be less able to prepare for or respond to extreme events.How can we stop climate change in 2022? ›
- 1Switch on renewable energy.
- 2Make buildings more efficient.
- 3Turn cities clean and green.
- 4Rev up electric vehicles — and walk or bike the rest of the way.
- 5Sink carbon back into the land.
- 6Invest in a fairer world.
A paper published by the Anglia Ruskin University in the United Kingdom has identified five countries in geographical locations with “favourable starting conditions” that may allow them to be less touched by the effects of climate change: New Zealand, Iceland, the United Kingdom, Australia, and Ireland.Is global warming the same as climate change? ›
“Climate change” encompasses global warming, but refers to the broader range of changes that are happening to our planet. These include rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times.What is the causes and effects of climate change? ›
Human activities, such as burning fossil fuels and destroying rainforests, have an increasing influence on the climate and the Earth's temperature. This adds huge quantities of greenhouse gases to those naturally present in the atmosphere, increasing the greenhouse effect and global warming.What are two benefits of climate change? ›
Reducing air pollution from emissions of fossil fuels and the accompanying health and environmental impacts is the most obvious co-benefit, but there are many other areas, including resource efficiency, economic security, sustainability of ecosystems or increased economic dynamism where positive impacts can be expected ...
- Fossil fuels. Expand Autoplay. ...
- Deforestation. ...
- Increasing livestock farming. ...
- Fertilisers containing nitrogen. ...
- Fluorinated gases.
- Changes in Rainfall Patterns. ...
- Increase in Sea Level. ...
- Loss of Wildlife Species. ...
- High Temperatures. ...
- Shrinking of Arctic Ice. ...
- Stronger Storms and Hurricanes. ...
- Prolonged Heat Waves. ...
- Spread of Disease and Economic Losses.
The climatic change has become a global concern over the last few decades. Besides, these climatic changes affect life on the earth in various ways. These climatic changes are having various impacts on the ecosystem and ecology. Due to these changes, a number of species of plants and animals have gone extinct.How do you start a topic sentence for climate change? ›
Topic Sentence: Climate change is natural, but in the last few hundred years it has been artificially sped up. Second Cause: Places are becoming over populated. There is also deforestation. Topic Sentence: Climate Change also effects the Earth's ecosystem in many ways.What does anthropogenic change mean? ›
Anthropogenic changes are alterations that result from human action or presence. They may be deliberate, such as when land is cleared for agriculture, modifying landscapes and introducing new species.What are the main anthropogenic? ›
There are two principal sources of anthropogenic emissions: land use conversion and fossil fuel combustion.What causes anthropogenic pollution? ›
Most human-made air pollution comes from burning fossil fuels for transportation, electricity, and industry. Common pollutants produced by engines that burn fossil fuels are carbon dioxide, nitrogen oxides, sulfur dioxide, volatile organic compounds (VOCs), and particulates.What are anthropogenic threats? ›
Threat: any human activity or process that has caused, is causing, or may cause the destruction, degradation, and/or impairment of biodiversity and natural processes (Salafsky et al. 2003).What are the anthropogenic causes? ›
Anthropogenic factors constitute the primary deterministic causes of species declines, endangerment and extinction: land development, overexploitation, species translocations and intro- ductions, and pollution. The primary anthropogenic factors produce ecological and genetic effects contributing to extinction risk.What is meant by anthropogenic causes? ›
Definition: Scientists use the word “anthropogenic” in referring to environmental change caused or influenced by people, either directly or indirectly.
Important anthropogenic factors are groundwater exploitation, deliberate modification of groundwater storage (by artificial drainage or by artificial recharge), land use type and land use practices (influencing groundwater quantity and quality), and the production and management of waste and wastewater.What are the effects of anthropogenic? ›
Humans alter species interactions by introducing species and altering habitats by removing native vegetation, building structures and transforming landscapes. If native species can evolve in response to these impacts, then they are less prone to extinction.How do anthropogenic activities affect the environment? ›
Impacts from human activity on land and in the water can influence ecosystems profoundly. Climate change, ocean acidification, permafrost melting, habitat loss, eutrophication, stormwater runoff, air pollution, contaminants, and invasive species are among many problems facing ecosystems.What is the biggest contributor to anthropogenic climate change? ›
Fossil fuels – coal, oil and gas – are by far the largest contributor to global climate change, accounting for over 75 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions. As greenhouse gas emissions blanket the Earth, they trap the sun's heat.