We know that human activities have substantially increased the concentration of carbon dioxide in the atmosphere during the past two centuries, and that carbon dioxide is one of the most important contributors to the atmospheric 'greenhouse effect.
(carbon dioxide; is; one of the most important contributors to the atmospheric 'greenhouse effect) (We; know; that human activities have substantially increased the concentration of carbon dioxide in the atmosphere during the past two centuries, and that carbon dioxide is one of the most important contributors to the atmospheric 'greenhouse effect)
carbon dioxide We
is know
one of the most important contributors to the atmospheric 'greenhouse effect
that human activities have substantially increased the concentration of carbon dioxide in the atmosphere during the past two centuries, and that carbon dioxide is one of the most important contributors to the atmospheric 'greenhouse effect