MADRID, April 21 (Xinhua) -- Thousands of people marched through the Spanish capital of Madrid on Saturday, demanding measures to reduce carbon dioxide emissions and keep climate change within limits.

    The march, aimed at marking Earth Day on April 22, was sponsored by Greenpeace and local environmental groups.

    The marchers said in a statement that governments should take emergency measures to reduce greenhouse gas emissions, a major environmental problem faced by all human beings.

    The statement also called on developed nations to cut 30 percent of greenhouse gas emissions by 2020.

    Spaniards in other cities also held similar events to celebrate Earth Day.