Meanwhile a Latvian energy expert criticized the national energy company here for a short-sighted policy of importing electricity from Russia, rather than generating it from windmills.
In a letter to U.S. Ambassador to Latvia James Holmes, which protesters handed to a security guard through the bars that surround the embassy, Arvids Ulme, president of the Environmental Protection Club, said the United States should "feel global responsibility, as other countries have done, and act to approach global problems." The United States must realize that "people are above profit," the letter continued.
Echoing tactics used at The Hague conference, from which several protesters had just returned, they produced a bag of sand from The Hague and said they were ready to show embassy staff how to build a dike to protect the building from rising sea levels, which scientists believe will result from global warming.
The United States accounts for 5 percent of the world's population but produces 25 percent of the world's greenhouse gas emissions, say environmentalists. It refused to implement the climate change convention which it signed in Kyoto in 1997, after other nations rejected its plans to avoid cutting emissions by buying so-called carbon credits from countries in which carbon emissions have fallen below 1990 levels, as has happened in much of Eastern Europe since the collapse of communist-era heavy industries.
An Estonian bus carried 60 Estonian environmentalists, five Latvians and nine Lithuanians across Europe to The Hague, where they joined 5,000 people who built protective dikes 1.5 meters high and totaling 500 meters in length around the conference center.
Protest organizer Alda Ozola from Riga said she was impressed by the number of people who had come from countries largely unaffected by global warming.
"We were very disappointed by the failure of the meeting," she said.
"There was such a positive atmosphere as we built the dikes. It's not easy to mobilize people unless they have lost their jobs."
Paulis Barons, an energy adviser to the Latvian branch of the environmental group Coalition Clean Baltic, acknowledges the need for economic growth in Latvia, which could increase the country's carbon dioxide emissions. But while emissions per capita are eight to 10 times lower than in Western Europe, more could be done to limit them, he said.
In the heating sector, which accounts for 40 percent of Latvia's energy consumption, efficiency is expected to improve with the building of new cogeneration gas power stations and improvements in the insulation of buildings, he said.
Between 60 percent and 90 percent of Latvia's electricity is generated at hydroelectric plants on the Daugava River. But much of the rest could be generated by windmills on and off the Latvian coast, says Barons. He criticized the Ministry of Economics and state energy company Latvenergo for a lack of enthusiasm for wind power.
"We shouldn't be so dependent on imported electricity," he said.
"Energy generation from windmills on and off the Latvian coast would be viable. But Latvenergo associates the development of alternative energy sources with pressure for privatization. They make profit margins of around 200 percent from imported electricity. But this electricity comes from the Ignalina nuclear power plant in Lithuania, which is soon to be closed, from Estonia, which generates electricity by burning oil shale - a serious pollutant - and from Russia."
Meanwhile in Lithuania, environmentalists seem unsure how energy should be produced, particularly after the closure of the nuclear power station at Ignalina.
Government plans to dam rivers for electricity generation will harm the already endangered salmon population, says Pranas Mierauskas, director of the Lithuanian Fund for Nature. Generating heat by burning peat and timber would be less polluting than burning oil, he says, but would damage the ecosystem, in which peat bogs play an important role.
"We're glad Ignalina is closing. It's unsafe," said Mierauskas.
"But the way forward might be to build new, safe nuclear power stations. This would be expensive though."
International environmental groups such as Friends of the Earth are hoping further talks in May between the world's biggest producers of greenhouse gases will be more successful.