I don't know the exact figure (because I didn't spend enough time looking for it).
But the IPPC FAQ pages include this statement: "Since the start of the industrial era (about 1750), the overall effect of human activities on climate has been a warming influence. The human impact on climate during this era greatly exceeds that due to known changes in natural processes, such as solar changes and volcanic eruptions." http://ipcc-wg1.ucar.edu/wg1/FAQ/wg1_faq-2.1.html
Good source for answers on climate is from climate scientists is RealClimate at http://www.realclimate.org/index.php/archives/2008/07/once-more-unto-the-bray/#more-583.
Like most things, finding answers on climate change is a tricky business. There are probably many more sites maintained by people who know nothing about science or just enough to confuse themselves than there are maintained by scientists who don't have a lot of spare time. Furthermore, there are vested interests in maintaining the status quo who seek high and wide for contrarian scientists to make it seem as though there's a debate about whether or not global warming is taking place. There is, but not among climatologists. A recent University Of Chicago survey considered the views of scientists in many fields on the subject: http://www.sciencedaily.com/releases/2009/01/090119210532.htm.
Sorry I don't have a more precise figure, but you can find good estimates online. Just consider your sources.
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move
whales
Nene
it was the 50th state
Honolulu and Hilo.
Hawai'i Pono'i.
The Pacific Ocean
Sugar cane
migration in Hawaii
Jämęšjbusg m
sealevel (pacific ocean)