Widespread improvements in the quality of life of many of the world’s populations have gone hand-in-hand with increased demands on natural resources. The planet is struggling to keep up. Increases in the average global temperature, and the frequency of extreme weather events are transforming ecosystems around the world and threatening entire species of plants and animals. Forests are drying up because there is less rainfall and thus more fires, and the glaciers of both the North and South Poles are shrinking. The consequences of climate change affect all of us, but to react and adapt to these challenges, we must first understand them.



per million (ppm)


carbon dioxide (CO₂) concentration in the atmosphere is at its highest in the last 650,000 years.

Global temperature

1,1 °C

since 1880

Global temperature

Nineteen of the hottest years since 1880 were measured after the year 2000.

Arctic sea ice


per decade

Arctic sea ice

The Arctic is warming about 2 to 3 times faster than the rest of the planet. Every 10 years, about 13.1% of the mass of the Arctic ice sheet melts.

Ice sheets


tons per year

Ice sheets

Satellite data shows that the mass of the polar ice sheet is decreasing.

Global sea level


per year

Sea level

The average global sea level has risen by 190 mm in the last 100 years as a result of melting glaciers.Such rises can threaten coastal areas or port functions.

Climate, weather, and natural disasters


Climate is not the same as weather, but the two phenomena are closely related. While weather refers to short-term conditions that can change quickly, climate determines the long-term character of a given place, for instance, whether it is temperate or tropical. The relationship between weather and climate is crucial: the former is subordinate to the latter. Climate determines temperatures, weather diversity, the traits of winters, rainfall totals, as well as the nature of meteorological phenomena such as the severity of storms. It is due to this delicate relationship that we are facing both temperature rises and more frequent weather extremes and natural disasters as a result of climate change.

Source: Study: ATTRIBUTION OF Extreme Weather Events IN THE CONTEXT OF Climate Change People in Need and Climate

Climate phenomena

Extreme temperatures, drought, forest fires

Hydrological phenomena

Floods, mass movements

Meteorological phenomena

Tropical, extratropical, convective, and local storms

Geophysical phenomena

Earthquakes, tsunami, volcanic activity
Geophysical phenomena are not directly linked to climate and weather changes, although their effects are often extreme.

Number of natural disasters worldwide
Hurricane Andrew
Hurricane Ivan
Hurricane Katarina
Earthquake a tsunami in Japan
Hurricane Sandy
291 1980 total
904 2014 total

Planet earth
as a Greenhouse


Solar energy in the form of radiation reaches the earth, where two thirds of it is absorbed by the planet’s surface. The rest is reflected back into the atmosphere where greenhouse gases operate. These gases reflect the energy back to earth where it again converts to heat – this process keeps the planet habitable.This phenomenon is called the greenhouse effect. Naturally, with the increasing amount of greenhouse gases in the atmosphere, this effect intensifies, leading to global temperature rise. Excessive temperature rise due to human activity is called global warming.

What causes climate change?

Greenhouse gases occur naturally in the atmosphere. They let the sun's rays pass through, while absorbing the thermal energy radiated by the earth's surface, keeping our planet warm. Without enough of these gases, the earth would be as cold as Mars. Conversely, with an extremely high concentration, the earth would become too hot, much like Venus.

The main greenhouse gases in the earth's atmosphere are water vapour (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ozone (O3). Human activity has led to increases in concentration of all of these gases, with the exception of water vapour.

Source: NASA Source: Brittanica

Carbon dioxide

Carbon dioxide is one of the main greenhouse gases produced by human activity that contributes to climate change. The burning of fossil fuels, as well as ploughing, the melting of permafrost (permanently frozen soil), and the decomposition of organic matter, all contribute to increased levels of carbon dioxide. Huge amounts of carbonaceous matter in the form of oil and coal were buried deep in the earth during the Paleozoic Era. Large areas of horsetail, lycophyte plants, and marine plankton removed most of the CO₂ from the atmosphere, using it to grow and multiply. Overtime, the remains of these plants became sedimented at the bottoms of wetlands and seas and, in the absence of oxygen, they were turned into coal and oil. Through mining and burning this coal and oil, we are releasing this CO₂ back into the atmosphere. Interestingly, in the Proterozoic era, the concentration of CO₂ in the atmosphere was about 3 times higher than it is today—but the sun’s energy was approximately one third weaker, so the temperature was comparable to current conditions.


Methane is a greenhouse gas 30 times more potent at reflecting sunlight than CO₂. It is created through methane fermentation, in an environment with no access to oxygen, . Large amounts of methane are released during oil and gas extraction and transportation, through livestock farming, from landfills, and through rice cultivation. It is also formed at the bottom of dams and in the oceans, as well as in the estuaries of the world's rivers that contain water enriched with fertilisers. These conditions have led to the depletion of oxygen, leading to the formation of huge, oxygen-free zones. Today, these ‘dead zones‘ cover areas the size of entire continents.

Source: Nature Magazine

Nitrogen oxides

Nitrogen oxides are greenhouse gases 300 times more potent than CO2. The main sources of nitrous oxide emissions are the burning of fossil fuels in transport and industry, industrial agriculture, as well as the production of certain chemicals, including fertilisers. Therefore, the largest contributors are industrial agriculture, especially chemical fertilisers, and transportation. In addition to the properties of the greenhouse gas, nitrous oxide also damages the Ozone layer.

It is estimated that humans have cut down about half of all of the world’s forests. Most of the current deforestation is linked to burning and cutting down tropical rainforests – primarily for agriculture or grazing, the production of charcoal and, secondarily, for logging wood as a material. Although tropical rainforests cover only about six percent of the Earth's surface, they have a outsized impact on the global climate. Tropical forests have the highest photosynthetic productivity of all forests on Earthas well as the ability to cool the earth's surface. These attributes make tropical rainforests indespensible in mitigating global warming. They are also important centres of global biodiversity as they host a large proportion of the world's animal and plant species.

Source: National Geographic Source: The Food and Agriculture Organisation of the UN, 2020: The State of World’s Forests - Forests, biodiversity and people

The natural forces that contribute to climate change include the intensity of sunlight, volcanic eruptions, and changes in the concentration of naturally-occurring greenhouse gases. According to NASA, these natural phenomena are still relevant today, but their impact compared to human activity is too small or too slow for natural causes to constitute a major cause of the rapid warming observed in recent decades. Without human activity, the climate would have remained virtually unchanged for the last 100 years.

Source: NASA

Burning fossil fuels

For millions of years, the concentration of greenhouse gases in the atmosphere fluctuated only slightly; natural processes removed as many greenhouse gases from the atmosphere as were released. Problems emerged as we began to extract and burn fossil fuels on a large scale, thus releasing unprecedented amounts of CO2 into the atmosphere. The concentration of CO2 has increased by almost 50 percent since the Industrial Revolution.

Source: NASA

Man-made emissions

Burning fossil fuels for electricity, heat, in industry and in transportation; deforestation; overuse of chemical fertilisers; and industrial animal production all increase the concentration of greenhouse gases in the atmosphere, leading to global warming (more here). Future temperatures and the entire course of climate change are directly linked to the amount of greenhouse gases humans release into the atmosphere.

Melting eartch matter

Positive feedback: a vicious cycle

Along with these so-called anthropogenic emissions (emissions generated by human activity), greenhouse gases leaking from melting soil (permafrost) or, for example, from drying peat bogs, play an increasingly important role. These are not released directly by humans, yet we are indirectly responsible for them by the role we continue to play in the warming of the planet. At the same time, frozen or snow-covered surfaces reflect some of the sun's rays, and the melting of these surfaces darkens the Earth's, thus increasing its warmth.

Source: Intergovernmental Panel on Climate Change Source: NASA

Emissions by sector

The largest emitter of greenhouse gas is the energy sector. Other significant sources of greenhouse gases include transportation, industry (especially construction and mining), and agriculture.

Different human activities produce different greenhouse gases. For instance, agriculture produces methane most notably, while the burning of fossil fuels releases carbon dioxide especially.

Who are the biggest

Europe and the United States are mostly responsible for the current state of the atmosphere, having released more than 90 percent of the emissions that had accumulated in the atmosphere by the end of the 20th century. In recent decades, however, the rest of the world has begun to catch up. This is particularly true in the case of China, which is experiencing an unprecedented economic boom.

Source: Our World in Data

Where do emissions
get outsourced?


CO₂ emissions are usually measured in terms of their production on the territory of individual states. However, this calculation does not give us a complete picture of who is truly responsible for their creation. International companies often employ cheap labour in developing countries where they process raw materials, with the resulting emissions being attributed to the place of assembly, though the products are produced for markets in richer countries, such as Europe or the USA - these countries thus "import" emissions created elsewhere. Typical "exporters" of emissions are China and Russia, while the USA, Western and Northern Europe, as well as a number of African countries are typical “importers” of emissions.

The largest exporter CO2

To calculate consumption-based emissions, it is necessary to monitor the movement of goods around the world. Whenever goods are imported, the emissions resulting from their production must be attributed to the country which receives the goods and, conversely, deducted from the country which produces and exports the goods.

The red colour on the map represents net importers of emissions, while blue indicates net exporters. For example, 20 percent means that a country imports 20 percent of its domestic emissions.

Source: Our World in Data

Environmental inequality

Many of the countries that bear the most responsibility for greenhouse gas emissions are the least vulnerable to their consequences. Developing countries, which generally have less capacity to react and adapt, are the first to feel the most severe effects of climate change. They deal with the consequences in both temporary and permanent ways, such as migration. Thus climate change is an increasingly important issue in relations between developing and developed countries.

On environmental migration

Did you know that...

...approximately 1.6 tonnes of CO₂ are released during a standard, transatlantic, round-trip flight. This is almost as much as the average annual emissions of one person in India. The average US citizen produces about 10 tonnes of CO₂ each year through flying alone.

Celebrities including Paris Hilton, Jennifer Lopez, Emma Watson, and Bill Gates have such excessive carbon footprint that they have been labled “super emitters,” largely due to extremely frequent flying. Bill Gates, who in 2017 produced 1,600 tons of CO₂ with his private jet, is at the top of this ranking.

This shows another inequality in relation to climate change: although climate change will affect everyone on the planet, only a fraction of the planet's population lives are enhanced by the benefits of climatically disastrous activities.

Source: World Bank Group Source: The Independent

Degrees of global warming


Since the 19th century, the earth has warmed by about 1.1°C. A new United Nations report addresses the differing consequences of warming by 1.5° or 2°C.

Half a degree may not sound like much, but the effects of global warming, be it a few tenths of a degree, may create a dramatic difference: such a change has the potential to expose tens of millions of more people around the world to dangerous heatwaves, water shortages, and coastal floods. Half a degree could also mean the difference between a world with coral reefs and a year-round polar cap, and a world without them.

Source: Intergovernmental Panel on Climate Change

Hothouse Earth

If current rates of warming continue, the "Hothouse Earth" scenario, which assumes that most of the planet will become uninhabitable, may become a reality. According to this scenario, agriculture will be possible only in northern latitudes, the world’s deserts will expand, tropical rainforests will be devastated, glaciers will melt, some cities will sink, most terrestrial biodiversity and marine life will be destroyed, the Gulf Stream will slow down or even stop, and a drastic reduction in the planet's habitability will follow.

Carbon budget

The carbon budget is the remaining amount of greenhouse gases that humans can emit before the planet warms by 1.5°C (or 2°C depending on the set limit). These calculations, like other climate models, are based on climate modeling. Research shows that climate modeling tends to predict the evolution of emissions and related warming relatively accurately. The risk of exceeding the 1.5 or 2 ° C limit is therefore very real, and although predictions of when exactly this will occur may vary by decades, we must remember that in general, every tenth of a degree has implications for the quality of human life. Therefore, it is appropriate to apply the precautionary principle.

Source: Climate Coalition

Did you know that...

.... there is a so-called “climate clock” in New York which counts down how much time is left until we reach climate disaster? The countdown is based on the carbon budget.


One of the biggest challenges we will face as a result of climate change is the massive migration of people to the less climate-endangered areas. Given that large portions of our planet will become virtually uninhabitable, people will begin to move en masse in an effort to fulfil their basic needs. There will be local conflicts over land and resources− the worst-case scenarios envisage a global conflict− and other impacts, for instance, increasing gaps and segregation between the rich and the poor, and the disintegration of nation-states.

Emissions scenarios


Climate models

Climate models are complex simulations of the planetary system that attempt to calculate possible future climate scenarios. There are many of these models, and they are constantly evolving. Based on climate models and hypothetical emissions scenarios, climatologists can devise trajectories of global warming to the year 2100. The best-known emissions scenarios are called Representative Concentration Pathways (RCP), which show the evolution of global warming at various hypothetical levels of greenhouse gas emissions.

No climate policies

No climate policies

If no climate policies had been implemented, by the year 2100, the earth would warm by an estimated 4.1°C to 4.8°C relative to pre-industrial temperatures.

Current climate policies

Current climate policies

Based on current climate policies being implemented, by the year 2100, the earth is projected to warm by 2.8°C to 3.2°C.

National pledges

National pledges

If all countries achieve the targets and pledges set within the Paris Climate Accord, by the year 2100, the earth will warm by 2.5°C to 2.8°C, thus exceeding the agreement’s target to keep warming well below 2°C, and ideally under 1.5°C.

Consistent adherence to 2°C

Consistent adherence to 2 °

There are a range of emissions pathways that would enable us to limit average warming to 2°C by 2100. This would require a significant increase in the pledges made as part of the Paris Agreement.

1.5°C consistent

1.5°C consistent

Emissions pathways that would limit average warming to 1.5°C by 2100 would require an immediate and drastic reduction in global greenhouse gas emissions. For the time being, this scenario is highly unlikely.

Zdroj: Our World in Data

What awaits the Czech Republic?

Climate change has already reached the Czech Republic. The average temperature in the Czech Republic has risen by 2°C (compared to temperatures before the Industrial Revolution) – a degree higher than the global average. For years, we have been struggling with more tropical days and droughts, as well as more frequent fires, torrential rains, and flash floods. Therefore, it is necessary to adapt to the changing climate in time and start working on mitigation measures.

More on climate change in the Czech Republic

What can we do?

The changing climate is an existential problem for humanity, but we can bring about the necessary change. With social and political change, new technologies and management methods, and proper care, we can create an economy based on renewable resources and immaterialist patterns of behavior that will support us all without destroying the planet. However, a sustainable society requires us to understand and plan for our impact on the planet, and to learn to manage that impact. That, in turn, requires systemic changes, the promotion of science, the development of sustainable technologies, and a willingness on the part of individuals to change their behaviour.

More solutions to the climate crisis

The solution to the climate crisis lies in reducing our reliance on fossil fuels such as oil, carbon, and natural gas, and replacing them with renewable and cleaner energy sources, all the while increasing energy efficiency on the one hand, and the consumption of natural resources on the other. But effective change must come from above, starting at the level of international agreements and countries being truly committed to complying with them.

More than half of the world's population currently lives in cities, and this proportion is expected to increase to almost 70 percent by 2050. Cities are responsible for consuming two-thirds of the world's energy and producing more than 70 percent of global carbon emissions. Even minor adjustments to urban policies can thus be of great importance—from reducing waste production and promoting affordable and sustainable urban transport, to building green buildings and making carbon dioxide emissions more costly.

Zdroj: UN Zdroj: C40 Cities

Changing individual consumption habits alone willl not reverse climate change. Our individual behaviours and attitudes certainly play an important role. In addition, individuals have the power to exercise their rights as citizens and as consumers, and to pressure their governments and international organisations to make the necessary systemic changes.

Climate change and People in Need


We have been helping for more than 10 years

People in Need has been active in the struggle against climate change for more than a decade. We are working to help people around the world cope with its effects. We assist in crisis situations and we focus on prevention. We help communities with advocacy and with implementing innovative adaptation and mitigation measures. Help us fight climate change.

Activities of People in Need

Resources and materials

Distinguishing climate change facts from misleading claims and disinformation is critical in the fight against it. We have put together a list of reliable resources and materials to help you understand the topic.

Go to resources
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