The changes described—decreasing runoff, increasing temperature, and decreasing precipitation—suggest a scenario of drought or reduced water availability, which could lead to various environmental impacts.
Among the options provided, the most likely result of these changes would be:
A. Permafrost thawing
Higher temperatures can lead to the thawing of permafrost, especially in polar and sub-polar regions. This can release trapped greenhouse gases and further contribute to climate change. The other options are less directly connected to the changes outlined:
- B. Rivers flooding: This is typically associated with increased precipitation, not decreasing amounts.
- C. Sea ice forming: Warmer temperatures make it less likely for sea ice to form.
- D. Sea levels increasing: While this can occur due to other climate change factors, such as melting ice caps, the direct connection to the specific changes listed is weaker.
Thus, the logical choice is A. Permafrost thawing.