Climate Change Over the Past 100 Years. Global surface temperature has been measured since 1880 at a network of ground-based and ocean-based sites. Over the last century, the average surface temperature of the Earth has increased by about 1.0o F.

Neanderthals (Homo neanderthalensis) were discovered first in Germany’s Neander Valley in 1856. They emerged between 100,000 and 200,000 years ago, give or take, in the early and middle Paleolithic era, and they used tools, albeit very simple ones.

between 45,000 and 10,000 years ago

These experts calculate that between 0.01 and 0.1% of all species will become extinct each year. But if the upper estimate of species numbers is true – that there are 100 million different species co-existing with us on our planet – then between 10,000 and 100,000 species are becoming extinct each year.

What are the consequences of extinction? If a species has a unique function in its ecosystem, its loss can prompt cascading effects through the food chain (a “trophic cascade”), impacting other species and the ecosystem itself.

Scientists have also discovered links between the incidence of West Nile virus and hantavirus and local reductions in biodiversity. Animal extinctions may also rob humans of valuable medical advancements. Many different species have unique bodily processes that can offer insight into curing human disease.

Plants and animals maintain the health of an ecosystem. And, when species become endangered, it’s a sign that an ecosystem is out of balance. But the balance within an ecosystem isn’t always easy to maintain: the loss of one species often triggers the loss of others. …