Life experiences climate change unevenly across local microclimates

A global review finds that climate change is not experienced uniformly across forests, fields, hillsides and other local environments. Changes in vegetation, cloud cover, topography, soil moisture and atmospheric conditions can alter near-ground temperatures at rates that differ substantially from regional averages, potentially changing how species encounter heat and respond to warming. The analysis, led by Stockholm University researcher Caroline Greiser and published in Global Change Biology, synthesizes the processes that can either buffer organisms from regional warming or expose them to faster local temperature increases.

Most organisms do not live under the climatic conditions represented by a weather station or a large-scale climate model. They occupy smaller habitats, including forest interiors, patches of shrubs, shaded slopes and sunlit ground, where temperature and other conditions can differ markedly from the surrounding region. These near-surface environments form a microclimate. The review concludes that a microclimate need not change in the same way as its regional climate: local temperatures may warm more slowly, remain relatively stable or, in some circumstances, rise faster than the broad-scale average. A single regional warming figure can therefore conceal contrasting thermal experiences across very short distances.

Vegetation is one of the principal drivers highlighted in the review. As climate change alters forests, shrublands and other plant cover, vegetation can modify both incoming solar energy and the transfer of heat from the ground to the atmosphere. Shrubs and trees are not simply passive indicators of climate change; their presence changes the local energy balance under which organisms live. One model simulation considered the expansion of shrubs and trees into open steppe in Turkey. On the hottest days, shrub encroachment produced near-ground air temperatures up to 16 degrees Celsius lower than in open areas, while the open locations warmed more rapidly under a regional warming scenario. The simulation illustrates how a biological change can create a different local climate trend within the same regional landscape.

Atmospheric changes can compound these contrasts. Cloud cover influences how much solar radiation reaches the surface, so reduced cloudiness can substantially increase heating in exposed locations. Shaded habitats, including forest interiors and pole-facing slopes, may be less affected by the same change. These effects interact with topography, vegetation, soil moisture and other characteristics, producing microclimates that can diverge over small spatial scales. Until recently, researchers faced major difficulties in tracking such variation across broad areas and long periods. New sensor networks, expanded long-term datasets and mechanistic models are beginning to make it possible to connect changes in the atmosphere and vegetation with the conditions organisms actually encounter. The authors emphasize that this work requires collaboration between atmospheric scientists and ecologists because the controlling processes span both physical and biological systems.

For biodiversity research, the implication is that regional climate data alone may provide an incomplete account of climate exposure. An area may show regional warming while particular habitats remain relatively buffered because of local shading, moisture or vegetation; elsewhere, local conditions may change more rapidly. Accurately capturing this variation could strengthen predictions of future species distributions and ecological interactions and help identify where organisms are likely to face greater climatic stress. The review does not establish specific conservation outcomes, but it identifies microclimate information as a necessary component for understanding where species may persist and where they may be vulnerable. Its broader conclusion is that climate change must be understood not only as a change in regional averages, but also as a patchwork of local experiences shaped by interactions among climate, land cover and landscape structure.

Subject of Research: Drivers and mechanisms of microclimate change experienced by organisms under global climate change

Article Title: How life on Earth experiences climate change

Article References: How life on Earth experiences climate change. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

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Keywords: microclimates, climate change, biodiversity, vegetation, temperature, regional warming, land cover, species distributions, atmospheric science, life, Earth, experiences