Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, synthetic fragrances, and plastics.Oil accounts for a large percentage of the world's energy consumption, ranging from a low of 32% for Europe and Asia, to a high of 53% for the Middle East.It is generally accepted that oil is formed mostly from the carbon rich remains of ancient plankton after exposure to heat and pressure in Earth's crust over hundreds of millions of years.Even though the Industrial Revolution generated an increasing need for energy, this was initially met mainly by coal, and from other sources including whale oil.However, when it was discovered that kerosene could be extracted from crude oil and used as a lighting and heating fuel, the demand for petroleum increased greatly, and by the early twentieth century had become the most valuable commodity traded on world markets.[9][10] At the turn of the 20th century, Imperial Russia's output of oil, almost entirely from the Apsheron Peninsula, accounted for half of the world's production and dominated international markets.[12] As a side effect of these early developments, the Apsheron Peninsula emerged as the world's "oldest legacy of oil pollution and environmental negligence".[15] Some historians challenge Canada's claim to North America's first oil field, arguing that Pennsylvania's famous Drake Well was the continent's first.[19][20][21][need quotation to verify] In the first quarter of the 20th century, the United States overtook Russia as the world's largest oil producer.Germany, cut off from sea-borne oil supplies by Allied blockade, failed in Operation Edelweiss to secure the Caucasus oil-fields for the Axis military in 1942, while Romania deprived the Wehrmacht of access to Ploesti oilfields – the largest in Europe – from August 1944.Important developments since World War II include deep-water drilling, the introduction of the drillship, and the growth of a global shipping network for petroleum – relying upon oil tankers and pipelines.In 1949 the first offshore oil-drilling at Oil Rocks (Neft Dashlari) in the Caspian Sea off Azerbaijan eventually resulted in a city built on pylons.[46] Edward Teller explained that carbon dioxide "in the atmosphere causes a greenhouse effect" and that burning more fossil fuels could "melt the icecaps and submerge New York".[46] The Intergovernmental Panel on Climate Change, founded by the United Nations in 1988, concludes that human-sourced greenhouse gases are responsible for most of the observed temperature increase since the middle of the twentieth century.