Key terms

Carbon neutrality means having a balance between the amount of carbon dioxide released into the atmosphere and the amount of carbon dioxide absorbed (mostly by natural environments such as forests and oceans). Carbon dioxide is the primary greenhouse gas released through human activities.

Climate change is when there is a big difference in normal climate patterns over a long period of time. Weather and climate are two different things. Weather is what we experience in the moment; climate describes the broader trends that make certain weather experiences more or less likely.

Extreme heat is defined as summertime temperatures that are much hotter and/or humid than average. Because some places are hotter than others, this depends on what’s considered average for a particular location at that time of year. Extreme heat increases the risk of heat-related illnesses, like heat exhaustion or heat stroke, that can worsen pre-existing health conditions. In extreme situations, these illnesses can lead to permanent disability or death.

Greenhouse gases are certain gases (both natural and human-made) in the atmosphere (e.g. water vapor, carbon dioxide, nitrous oxide, and methane) that trap energy from the sun. The trapped energy causes the Earth’s temperature to rise – this is called the greenhouse effect.

Without greenhouse gases, heat would escape back into space and Earth’s average temperature would be -18°C. Human activities over the last 150 years, however, have led to an increase in greenhouse gas emissions, a rise in global temperatures (global warming), and climate change.

Low carbon means producing low levels of the greenhouse gases that are driving global climate change (mainly carbon dioxide, which is released through a wide variety of human activities such as deforestation and the burning of fossil fuels).

Sea level rise is an increase in the level of the world’s oceans that is happening because of global climate change. Sea level rise poses a serious threat to waterfront areas around the world. Consequences include increased flooding during high tides and storm surges, as well as water levels that gradually increase along the shore.

Zero emissions means that an energy source emits no waste products that pollute the environment or disrupt the climate.