Final answer:
Latitudinal temperatures by 2100 AD are projected to be greatest in the Arctic and other high latitude regions of the Northern Hemisphere, as suggested by the IPCC AR4 multi-model climate projection.
Step-by-step explanation:
The IPCC AR4 multi-model climate projection suggests that latitudinal temperatures by 2100 AD will be greatest in the higher latitudes, particularly in the Arctic and other high latitude regions of the Northern Hemisphere. This is due to a combination of factors, including the albedo effect where melting snow and ice reduce the Earth's reflectivity, leading to more heat absorption. Future climate change is not only limited to rising temperatures but also includes changes in patterns of precipitation, and in aquatic ecosystems, the temperature and pH levels are critical. Additionally, regions such as Australia, the Argentine pampas, the American southwest, and the prairie pothole region of North America are experiencing drying trends that further compound the effects of climate change.