| 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). |
| Impacts | The consequences of hazards realized in natural and human systems, where risks result from the interactions of climate-related hazards (including extreme weather events) and vulnerability. Impacts generally refer to effects on life, livelihoods, health and well-being, ecosystems and species, economic, social and cultural assets, and infrastructure. Impacts can be referred to as consequences or outcomes and can be adverse or beneficial. |
| Mitigation of climate change | Human intervention through strategies, options or measures to reduce the source or increase the sinks of greenhouse gases (GHG) responsible for climate change. Examples of mitigation measures are the use of renewable energy sources, waste reduction processes, use of public transport, among others. |
| 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 | Usually presented as the probability of occurrence of an event multiplied by the impact caused by that event. In the context of climate impact assessment, the term risk is often used to refer to the potential for adverse consequences of a climate-related hazard, or adaptation or mitigation responses to it, on life, livelihoods, health and well-being, ecosystems and species, economic, social and cultural assets, and infrastructure. |
| Climate action | Climate action involves intensified efforts to reduce GHG emissions and strengthen resilience and adaptive capacity to climate-induced impacts, including climate-related risks; integration of measures into national policies, strategies and planning; improved education, awareness raising and personal and institutional capacity building on climate change response, adaptation and mitigation. |
