Gleneagles, Scotland ? President Bush and the leaders of seven other top industrial countries pledged Friday to double aid for Africa in five years and substantially raise it for other poor countries, capping a summit conducted in what British Prime Minister Tony Blair called the “shadow of terrorism.”

Blair failed to convince Bush to embrace mandatory caps on greenhouse gas emissions and the summit issued instead a watered-down pledge to take other steps to combat global warming, such as technology development. World leaders will meet Nov. 1 to discuss new ways to combat slowly rising temperatures, Blair announced.

The aid accord was a victory for Blair, the summit’s host, who has made helping Africa a top priority of his government. Some activists complained that the planned increase to $50 billion a year in 2010 was too slow, but Blair won praise from the Irish rock star Bono and other celebrities who staged concerts in 10 cities around the world last weekend to bring pressure on behalf of the world’s poor.

The summit, which brought together leaders of the Group of Eight industrialized countries and other heads of government, ended shortly before noon Friday so that Blair could return to the British capital, where bombs killed at least 49 people Thursday.

The attacks created a spirit of solidarity among the G-8 leaders that seemed to ease the way for compromise on Africa as well as on the Middle East. For that region, the leaders promised to spend up to $3 billion a year for the next three years to help build an independent Palestinian state. In addition to the United States and Britain, the group includes France, Germany, Italy, Russia, Canada and Japan.

The leaders promised that by 2010, overall aid to poor nations would rise by $50 billion, with half of the increase going to Africa. Although much of that increase consisted of pledges made in earlier initiatives, it got an unexpected boost from Japan, whose prime minister, Junichiro Koizumi, promised $10 billion in new funding over five years.

Global warming emerged as the most contentious issue of the three-day talks. Bush made it clear before, during and after the summit that the United States is inalterably opposed to the strict caps on greenhouse gas emissions contained in the Kyoto Protocol of 1997, which all G-8 countries except the United States have signed.