Final answer:
The current thermal environment can influence an organism's sensitivity to future temperature increases through the process of temperature acclimation. Predictive models suggest acclimated species might have a competitive edge in a warmer climate, though higher metabolic rates due to higher temperatures can impact energy and oxygen demands. Climate sensitivity parameters are critical for estimating the potential impacts of greenhouse gases on temperature changes.
Step-by-step explanation:
The sensitivity of an organism to future increases in temperature can be influenced by its current thermal environment. As organisms experience changes in climate, including increases in average temperatures due to factors like increased CO₂ concentrations, they may undergo a process known as temperature acclimation. This refers to physiological adjustments that enable them to better cope with changes in temperature. For example, plants may shift their maximum photosynthetic rate to align with new thermal conditions, although these adjustments may vary in response to the interplay between different processes like photosynthesis and respiration.
Predicted results from climate models suggest that if the average temperature in an ecosystem increases, species that have acclimated to warmer conditions may outcompete those that have not. This can lead to shifts in species distribution and population dynamics. However, if respiration increases more rapidly than photosynthesis, especially under stress conditions such as drought, the benefits of acclimation might be mitigated. Additionally, higher metabolic rates induced by higher temperatures might not always be beneficial, since they can lead to increased food and oxygen requirements.
Scientists predicting Earth's temperature rise consider how strongly climate features respond to increased greenhouse gas concentrations. The climate sensitivity parameter is estimated to be 0.8°C for every W/m² of additional radiative forcing, which provides insight into the potential severity of temperature changes in response to human activities.