The Earth has a layer of gases in its atmosphere that traps heat naturally. It's like a blanket that stops the planet from turning into a ball of ice. But over the last few centuries humanity has thickened this blanket by emitting more greenhouse gases (burning fuels and cutting down forests), causing the temperature to rise even higher.

These are molecules present in the air that block infrared radiation (heat). It is due to these gases that the heat that the planet radiates after receiving the sun's rays does not return to space.

In excess, greenhouse gases alter the Earth's climate: temperatures rise, evaporation increases, storms become stronger, droughts become longer, and the frequency of wildfires and floods increases.
Many people prefer to speak of “climate change” because not all extreme climate events are heat related: blizzards also become more intense in a warming world.

Carbon dioxide is the greenhouse gas most emitted by human activity, produced largely by the burning of fossil fuels, which, millions of years ago, were once organic matter. CO₂ is extremely long lasting: in air it has a half-life of 150 years on average. Only a small fraction of the carbon dioxide we emit today will still be warming the planet 10,000 years from now.

Methane is produced by microorganisms in soil, in the stomachs of ruminant animals, and in the decomposition of organic matter. It is also the main component of fossil fuels, which we use for heating our showers, cooking in the kitchen, and in transportation. Even when emitted in small quantities methane has the potential to warm the planet 28 times more than carbon dioxide over a period of one hundred years.

These are actions that curb greenhouse gas emissions – either by cutting emissions (using clean energy, such as swapping a gasoline-powered car for an electric one) or by capturing CO₂ from the atmosphere (when planting a tree, for example).

When prevention fails, adaptation comes into play: if we can't reduce emissions, we need to change our lifestyles. Adaptation can range from major engineering projects such as building large reservoirs to prevent flooding, to simple measures such as installing air conditioning in a school.

There are three types of fossil fuels: coal, oil, and fossil gas. They consist of the remains of microorganisms and plants that died in the distant past, baked slowly over millions of years deep within the Earth, that become long chains of carbon and hydrogen—hydrocarbons.

The "mark" each person leaves on the planet—whether individuals, a family, or an organization—is measured by the energy used and consumed. The wealthier the lifestyle, the larger the footprint: the richest 10% are responsible for two-thirds of the emissions that warm the planet.

The first universal agreement to combat the climate crisis – signed in 2015. The goals: to maintain warming below 2°C (preferably 1.5°C), adapt society to climate change, and align the global economy with decarbonization. To achieve this, all countries must submit targets to reduce emissions. More ambitious targets are set every five years.

Acronym for the Intergovernmental Panel on Climate Change — a team of hundreds of scientists who analyze climate change research, formed by the UN in 1988. Since 1990, six reports have been published, proving — beyond any doubt — that the climate is warming, that it's our fault, and that it will continue to get worse.

When we transform natural landscapes into farming areas or cities. For example, when a forest is cut down to create pasture: from environmental conservation to livestock farming.

The standard for measuring greenhouse gas concentrations: parts per million (ppm) and parts per billion (ppb). Today, there is about 420 ppm of CO₂ in the air—that is, for every million molecules, there are 420 of CO₂. This may seem low, but it's far above the natural level of the last 800,000 years, which has never exceeded 300 ppm.