@ERSpublications Climate change represents a threat to respiratory health by acting on respiratory diseases or their risk factors http://ow.ly/v6JElChanges in climate constitute a reality that, according to recent projections, is going to worsen in the coming years. Climate change represents a massive threat to respiratory health: 1) by directly promoting or aggravating respiratory diseases; or 2) by increasing exposure to risk factors for respiratory diseases. Climate change increases the amount of pollen and allergen produced by each plant, mould proliferation and the concentrations of outdoor ozone and particulate matter at ground level. The main diseases of concern are asthma, rhinosinusitis, chronic obstructive pulmonary disease (COPD) and respiratory tract infections. Groups at higher risk of climate change effects include individuals with pre-existing cardiopulmonary diseases or disadvantaged individuals. Adaptation and mitigation measures are strongly needed.It is now widely accepted that the earth's temperature is increasing, as confirmed by warming of the oceans, rising sea levels, glaciers melting, sea ice retreating in the Arctic and diminished snow cover in the Northern Hemisphere. Moreover, changes are also occurring in the amount, intensity, frequency and type of precipitation, as well as the increase of extreme weather events, such as heat waves, droughts, floods and hurricanes [1][2][3]. Most of the observed increase in globally averaged temperatures since the mid-20th century is probably due to the observed increase in anthropogenic greenhouse gas (namely carbon dioxide, methane and the nitrous oxides) concentrations [1]. Projections of future greenhouse gas emissions indicate a worsening of the situation with between a 1.1 and 6.4uC increase in the mean temperature by the end of the 21st century [1].Climate change represents a massive direct threat to respiratory health by promoting or aggravating respiratory diseases or indirectly by increasing exposure to risk factors for respiratory diseases [4]. Climate affects weather, air and water quality, local and national food supplies, economics and many other critical health determinants. Observational evidence indicates that regional changes in climate, particularly temperature increases, affect a diverse set of physical and biological systems in many parts of the world [1, 2], some of which are of concern for respiratory health. A rapid rise has been observed in the number of hot days, such as the 2003 heat wave where temperatures of o35uC were reached resulting in ,40 000 excess deaths across Europe, mostly for cardiopulmonary causes [5,6]. Sea levels have also started to rise as an effect of a regression of the polar ice packs. Both heat waves and melting ice have led to water deprivation in certain