Complete 5 pages APA formatted article: Ecological Effects of Climate Change Affecting the World Today. There have been wide variations in the sea–surface temperature (SST) during the Holocene period resulting in 3 definite cycles – warm to cold to moderate. Synchronous to this change, changes in the microfauna and marine productivity was also observed. Studies on the isotopic differences based on two planktonic species, one surface dweller – Globigerina bulloides and the other bottom dweller – Neogloboquadrina pachyderma indicate the level of oceanic stratification and productivity. It was found that during cool episodes, a vertical gradient in temperature existed resulting in intense vertical mixing, which in turn increased marine productivity. The vice versa was true during warm episodes resulting in low productivity.Changes in the terrestrial ecosystems of islands have also been noticed during the Holocene period. Studies (high resolution & Total Inorganic Carbon) and records of Lake Pyramid and Lake Owens show that 5 distinct climatic episodes – cool period followed by a dry period (11.6 – 10 ka) interspersed with a wet episode predominated the early Holocene period. The latter part of the early Holocene (10-8 ka) was mostly wet resulting in a substantial body of water in Lake Owens and movement of water from Lake Tahoe to Lake Pyramid.A case in the study has been the Channel Islands off the Southern Coast of California. These islands can be divided into the Northern (consisting of San Miguel, Santa Cruz, Santa Rosa, and Anacapa Islands) and Southern (consisting of Santa Barbara, Santa Catalina, San Clemente, and San Nicolas). Differences have been observed in the evolutionary patterns of these 2 groups of the Channel Islands. The southern islands are far removed and isolated from the mainland which has resulted in high levels of endemism in plant species as well as low diversity in flora and fauna. However marine productivity in these regions was high, primarily due to variations in SST. The Northern Channel Islands have shown high levels of human habitation during the Holocene period.