| Climate change | Change in climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and is additional to natural climate variability observed over comparable time periods. |
| Global warming | The process of increasing the average temperature of the Earth's oceans and atmosphere caused by massive emissions of gases that intensify the greenhouse effect, resulting from a range of human activities, especially the burning of fossil fuels and changes in land use (such as deforestation), as well as from various other secondary sources. |
| Adaptive capacity | The ability of a system, institution and mankind to adjust to different potential impacts, taking advantage of opportunities or responding to the consequences that might result. |
| Climate | Climate in a strict sense is generally defined as the average climate or, more rigorously, as the statistical description in terms of the average and variability of relevant quantities over a period ranging from months to thousands or millions of years. The classical period for the average of these variables is 30 years (climatological normal), as defined by the World Meteorological Organization. The relevant quantities are mostly surface variables, such as temperature, precipitation and wind. |
| Adaptation to climate change | In relation to humans, it is the process of adapting to the current or expected climate and its effects, to moderate harm or exploit beneficial opportunities. In natural systems, it is the process of adjusting to the current climate and its effects; human intervention can facilitate adjustment to the expected climate and its effects. |
| Extreme weather event | Weather events that are rare at a particular place and time of year. When an extreme weather pattern persists for some time, such as a season, it can be classified as an extreme weather event, especially if it generates an average or total that is itself extreme (e.g., drought or severe rainfall over a season). |
| Exhibition | The presence of people, livelihoods, environmental services and resources, infrastructure or economic, social or cultural assets in places that could be negatively affected. |
| Heatwave | A period of six days when the maximum air temperature is 5ºC higher than the average value of daily maximum temperatures in the reference period (1961-1990). |
| Risk | Probability of occurrence of an event multiplied by the impact caused by that event. |
| Disease vector | A living creature capable of transmitting an infectious agent, either actively or passively. |
| Climate vulnerability | The degree to which a system is susceptible to and unable to cope with the adverse effects of climate change, including climate variability and extremes. |
