Increased government alarm about global warms reflects the concern among scientists that such warming is occurring, though when to expect major effects is still in dispute.
What is the meaning of the above sentence?
It should be: “Increased government alarm about global warming reflects the concern among scientists that such warming is occurring, though when to expect major effects is still in dispute.”
It means that scientists believe the world’s climate is getting hotter. This is causing governments to become worried. But people disagree about when large effects of this warming will occur.