Human activities, including fossil fuel combustion, farming, and deforestation, are known to increase the levels of carbon dioxi
de, methane, and nitrous oxides in our atmosphere. Measurable warming of Earth due to these greenhouse gases can alter ecosystem dynamics. In addition to the direct climatic effects on organisms within biomes, warming can lower levels of sea ice and increase precipitation in Arctic areas. Global warming also can increases sea surface temperatures, which can subsequently melt permafrost in the tundra and increase the intensity of hurricanes in vulnerable areas. Within communities, climatic change can shift interdependent species "out-of-sync," potentially causing indirect loss of species. If the climate warms significantly, tundra permafrost may melt. This may next lead to ________ in the community.
Primary succession, in the context of environmental sciences, refer to the evolution of an ecosystem over a certain period of time. For this condition to occur, sudden changes to the environment (such as described in the question) that are irreversible must have taken place. These changes would cause the current ecosystem to gradually go extinct – from its plants to its animals. With the new changes, a new ecosystem would take its place – species that could exist in the new ecosystem would procreate, perhaps even thrive more if the new environment is more suitable to them.
This historian would be using "research skills" at this stage of the process, since he or she has yet to determine all the facts, and therefore is unable to yet form a thesis.
