More than 11,000 scientists from 153 countries have sounded the alarm on climate change. In a paper （publish）last week in the journal BioScience, they signed a declaration（声明）stating clearly that planet Earth is facing a climate emergency, saying that if no changes （make）, the world will face untold suffering. The evidence that the scientists collected reveals an undeniable truth human activities have been causing global warming from the fast rise of fossil fuel consumption the increase in greenhouse gas emissions（排放）over the past 40 years.
The scientists also gave some instructions to fight against global warming, proposing six actions to prevent （far）disasters: stabilizing population （grow）by investing into family-planning services and girls' education, replacing fossil fuels, cutting the emissions of climate pollutants, eating less meat, restoring and protecting （ecosystem）, and building carbon-free economy.
The scientists say the climate crisis is （close）related to human activities, so they call on people （change）their life styles. But these measures are comparatively abstract. Therefore, it is high time for policymakers to figure out more practical measures that can bring down carbon emissions.
