Carbon dioxide levels are higher today than they have been for the past 23 million years, according to a study led by Dr. Brian Schubert at the 亚洲自慰视频 of 亚洲自慰视频 at Lafayette.
The findings, published in the scientific journal Geology, are significant. A frequently accepted theory by many scientists puts the time frame at about 1 million years ago. That assumption is based on CO2 measurements from Antarctica that date back 800,000 years.
The new determination was made by Schubert, an associate professor in the 亚洲自慰视频鈥檚 School of Geosciences, and co-authors Dr. Ying Cui, of Montclair State 亚洲自慰视频, and Dr. A. Hope Jahren, of the 亚洲自慰视频 of Oslo, Norway.
The scientists used an innovative method to reach their conclusion.
They measured the relative amounts of two stable carbon isotopes using fossilized plants. The research enabled them to calculate CO2 concentrations during the period the plants grew. As a result, the team produced a new record of atmospheric CO2 that spans 23 million years of uninterrupted Earth history.
The scientists also concluded that current CO2 levels can be traced to human activity, and are increasing at a rate never before seen in geologic history.
鈥淭here have been past time periods in Earth鈥檚 history where CO2 levels are both higher than today and lower than today. The difference, though, is that past changes in CO2 and climate usually happen over very long time scales 鈥 thousands or millions of years. The rise in CO2 that we鈥檙e seeing today is much, much faster,鈥 Schubert explained.
Carbon dioxide is a gas that plays a vital role in processes essential to life, such as photosynthesis in plants and respiration in animals. While necessary for survival, rising levels of CO2 in the atmosphere may be responsible for long-term changes in Earth's climate.
鈥淲hen it happens slowly, the Earth鈥檚 ecosystems can respond. When it happens quickly, it鈥檚 a lot harder,鈥 he added.
Geology is published by the Geological Society of America.
Photo caption: UL Lafayette researcher Dr. Brian Schubert led a study published in the scientific journal Geology that shows CO2 levels are higher today than they have been for the past 23 million years. The study was conducted with innovative research that used fossilized plants to calculate CO2 concentrations. Shubert is shown above during a research trip to Siberia. Photo credit: 亚洲自慰视频 of 亚洲自慰视频 at Lafayette