New Delhi (PTI) The US will no longer dominate the global markets in the 21st century as the economic centre of gravity will shift to Asia which will produce over half the world's income, a top UN official says.

"The 21st century will overturn many of our basic assumptions about economic life. The 20th century saw the end of European dominance of global politics and economics. The 21st century will see the end of America dominance," writes noted economist Jeffrey Sachs in "Common Wealth: Economics for a Crowded Planet".

"New powers, including India, China and Brazil, will continue to grow and will make their voices increasingly heard on the world stage," says Sachs, who is a special adviser to UN Secretary General Ban Ki-moon on the Millennium Development Goals.

"The challenges of sustainable development -- protecting the environment, stabilising the world's population, narrowing the gaps between rich and poor and ending extreme poverty -- will take centre stage. Global cooperation will come to the fore. The very idea of competing nation-states that scramble for markets, power ad resources will become passe," he says.

In the book, Sachs analyses and addresses the great, interconnected, global challenges of the 21st century. A series of cascading threats to global well-being -- the most significant being environmental degradation and rapid population growth -- bear down upon our increasingly crowded planet. All of them are solvable, Sachs argues, but potentially disastrous if left unattended.