● Temperature extremes. Turtles are ectotherms - they regulate their body temperature by environmental means such as sun basking or moving into shade and moving to cooler or warmer water. Changes in seasonal climate patterns and extremes in hot or cold temperatures may stress turtles and cause some areas to no longer be suitable for certain heat-sensitive species. Some turtle species have temperature-dependent sex determination and higher temperatures could results in a skewed sex ration, with only female offspring being produced.
● Drought and fire frequency & duration. Turtles are sensitive to drought conditions that dry up water bodies - it is a loss of habitat and may force them to migrate in search of persisting water. Terrestrial turtles are at risk of injury or death when fires are frequent and intense, and frequent fires can result in vegetation changes that affect habitat suitability.
● Habitat degradation & loss. Changes in hydrology and plant cover driven by climate change will affect habitat quality for turtles. As climate changes, previously suitable habitats may become unsuitable.
● Altered incubation temperatures. For most turtle species, sex is determined by temperature of the environment at a critical stage of embryo development. Embryo development rate, size, and overall viability is affected by incubation temperature.
● Loss of nesting habitat. Changes in hydrology due to changes in precipitation and evaporation and changes in vegetation due to changing climate may affect the distribution and quality of turtle nesting habitat.
● Increased inland flooding. Increases in the intensity and frequency of flooding, and the timing of flood events, may increase habitat for aquatic turtles, but may also inundate nests and alter shoreline vegetation in ways that reduce habitat quality for semi-aquatic turtles. Floods may transport into streams and rivers pollutants that degrade water quality.
● Sea level & temperature rise. Sea level rise may inundate traditional nesting sites for estuarine and sea turtle nesting, and result in loss of salt marshes and other estuarine habitats. Estuary and tidal river water will become more saline as sea level rises