Both speleothems and marine 14C records are depleted in 14C compared to the atmospheric levels via a dead carbon fraction and marine reservoir age, respectively. This depletion is likely to dampen atmospheric 14C variation and may also result in calibration datasets that diverge over time if not ...
Atmospheric Carbon Dioxide Levels Over Phanerozoic Time A new model has been constructed for calculating the level of atmospheric CO$_2$ during the past 570 million years. A series of successive steady states fo... Berner,A R. - 《Science》 被引量: 687发表: 1990年 A 300-million-year reco...
No Comments on Atmospheric Carbon Dioxide Reached the Highest Levels in 800,000 years To limit global warming to 1.5-2 °C by 2100 (relative to pre-industrial temperatures), we'd need an urgent and rapid reduction in global greenhouse gas emissions. Image: PX Here According...
Synergistic effects of high atmospheric and soil dryness on record-breaking decreases in vegetation productivity over Southwest China in 2023 Zhikai Wang Wen Chen Tianjiao Ma ArticleOpen Access08 Jan 2025 A modified transformer model for the extended-range forecast of intraseasonal oscillation ...
Average annual atmospheric levels of carbon dioxide (CO₂) reached a record high of 421.08 parts per million (ppm) in 2023. Monthly atmospheric CO₂ concentrations peaked that year in May, at 424 ppm. Human activities have caused CO₂ concentrations to soar Annual CO₂ concentrations con...
Here we review and revise CO2 reconstructions from boron isotopes in carbonates and carbon isotopes in organic matter over the Cenozoic-the past 66 million years. We find close coupling between CO2 and climate throughout the Cenozoic, with peak CO2 levels of similar to 1,500 ppm in the Eocene...
The aerosol particle sizes range from 10−4to 10μm, falling under the following broad categories: sulfates, black carbon,organic carbon, dust, and sea salt. Aerosol concentrations and compositions vary significantly with time and location (Fu, 2014). Aerosol particles in the atmosphere are prod...
(Phys.org) —For the first time in human history, concentrations of the greenhouse gas carbon dioxide (CO2) could rise above 400 parts per million (ppm) for sustained lengths of time throughout much of the Northern Hemisphere as soon as May 2013. ...
Some reduction in SNR and spectral distortions can occur over these wavenumbers. Measurement of sample spectral lines of similar width to strong atmospheric lines in the same spectral region should performed under vacuum conditions. Stable residual carbon dioxide or water vapor absorption can produce a...
2), and global temperatures have reached 1.1 °C over preindustrial levels3. The Paris Agreement commits the world’s governments to limiting global temperature rise to 1.5 °C, or well below 2 °C4. The remaining carbon budgets associated with these boundaries are being rapidly ...