When British Petroleum and its drilling partners caused the Deepwater Horizon oil spill in the Gulf of Mexico in 2010, the US government demanded that BP finance the cleanup, compensate those who suffered damages, and pay criminal penalties for the violations that led to the disaster.

BP has committed more than US$20 billion in remediation and penalties. Based on a settlement last week, BP will now pay the largest criminal penalty in US history - US$4.5 billion.

The same standards for environmental cleanup need to be applied to global companies operating in poorer countries, where their power has been so great relative to that of governments that many act with impunity, wreaking havoc on the environment with little or no accountability. As we enter a new era of sustainable development, impunity must turn to responsibility. Polluters must pay.

For decades, major oil companies, including Shell, ExxonMobil, and Chevron, have been producing oil in the Niger Delta, an ecologically fragile environment of freshwater swamp forests, mangroves, lowland rainforests, and coastal barrier islands.

Twenty years ago, the International Union for Conservation of Nature and Natural Resources classified the Niger Delta as a region of high biodiversity of marine and coastal flora and fauna - tree species, fish, birds, and mammals, among other forms of life - and therefore rated it as a very high priority for conservation. Yet it also noted that the region's biodiversity was under massive threat, with little or no protection.

The global companies operating in the delta have spilled oil and flared natural gas for decades, without regard for the natural environment and the communities impoverished and poisoned by their actions. One estimate puts the cumulative spills over the past 50 years at about 10 million barrels - twice the size of the BP spill.

The data are uncertain: there have been many thousands of spills during this period - often poorly documented and their magnitude hidden or simply unmeasured by either the companies or the government. Indeed, just as BP was being hit with new criminal penalties, ExxonMobil announced yet another pipeline leak in the Niger Delta.

In the colonial era, it was the official purpose of imperial power to extract wealth from the administered territories. In the post-colonial period, the methods are better disguised.

Misbehavior protected

When oil companies misbehave in Nigeria or elsewhere, they are protected by the power of their home countries. Don't mess with the companies, they are told by the United States and Europe.

Last year, the United Nations Environment Program (UNEP) issued a remarkable report on Ogoniland, a major ethnic homeland in the Niger Delta that has been at the epicenter of conflict between local communities and international oil. The report was as scathing as it was scientifically clear.

Despite many past promises of a cleanup, Ogoniland remains in environmental agony, impoverished and sickened by the oil industry.

UNEP also offered clear and detailed recommendations, including emergency measures to ensure safe drinking water; cleanup activities targeting the mangroves and soils; public health studies to identify and counteract the consequences of pollution; and a new regulatory framework.

The world's governments have agreed to move to a new framework for sustainable development, declaring their intention to adopt Sustainable Development Goals at the Rio+20 Summit in June. The SDGs offer a critical opportunity for the world to set clear, compelling standards for government and corporate behavior. Many companies, including in the oil industry, have expressed their readiness to support sustainable development goals.

Cleaning up the Niger Delta would provide the strongest possible example of a new age of accountability.

Shell, Chevron, ExxonMobil, and other major oil companies should step forward and help to fund the necessary cleanup, ushering in a new era of responsibility.

Jeffrey D. Sachs is professor of sustainable development, professor of health policy and management, and director of the Earth Institute at Columbia University. He is also Special Adviser to the United Nations Secretary-General on the Millennium Development Goals. Copyright: Project Syndicate, 2012.www.project-syndicate.org. Shanghai Daily condensed the article.