相关实验视频
Updated: Jul 11, 2026

06:27
Simulating Impacts of Ice Storms on Forest Ecosystems
Published on: June 30, 2020
同位素证据表明,在普世时期,东非发生了剧烈的气候变化
T E Cerling1, R L Hay, J R O'Neil
1Department of Geology and Geophysics, University of California, Berkeley, CA 94720, USA.
Nature
|May 12, 1977
概括
古气候变化导致东非大约在1.8-2.0和0.5-0.6百万年前的降雨量大幅减少. 古代碳酸盐中氧同位素比率的变化证明了这一点.
科学领域:
- 古气候学 古气候学
- 同位素地球化学 同位素地球化学
- 东非古老环境 东非古老环境
背景情况:
- 重建过去的降雨模式对于理解气候动态和人类进化至关重要.
- 对pedogenic和地下水碳酸盐的氧同位素分析为古气候条件提供了可靠的代理.
相关概念视频
What is Weather?
Overview
What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
Responses to Heat and Cold Stress
Every organism has an optimum temperature range within which healthy growth and physiological functioning can occur. At the ends of this range, there will be a minimum and maximum temperature that interrupt biological processes.
Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.

