The data and research currently presented here is a preliminary collection or relevant material. We will further develop our work on this topic in the future (to cover it in the same detail as for example our entry on World Population Growth).
Over the past four and half decades – the time for which we have data – oil spills from tankers decreased very substantially.
The dataset by the International Tanker Owners Pollution Federation (ITOPF) covers more than four decades over which time the incidence of large oil spills from tankers greatly decreased. While in the 1970s there were 24.5 large (> 700 tonnes) oil spills per year, in the 2010s the average number of large oil spills decreased to 1.7 oil spills per year.
Both, large oil spills and medium sized oil spills (7-700 tonnes) are decreasing. This happened as the worldwide trade of petroleum and gas products increased. Included in the trade statistics is the trade of LNG, LPG, naphtha, gasoline, jet fuel, kerosene, light oil, heavy fuel oil and others, according to the source (UNCTAD).
ITOPF estimated that between 1970 and 2016 approximately 5.73 million tonnes of oil were lost as a result of tanker incidents. As single large incidents can be responsible for a huge share of all the oil spilled in a given year, it is advisable to look at trends or decade averages. Over these 43 years, the annual quantity of oil spilled decreased hugely. In the 21st century the quantity of spilled oil was smaller than in several single years in earlier decades. 2012 saw the lowest oil spillage on record so far: 1000 tonnes were spilled. The development can be seen in the following visualisation.