Quantitative estimates of past UV-B irradiance from fossil pollen
Informations
- Funding country
Norway- Acronym
- -
- URL
- -
- Start date
- 1/1/2021
- End date
- 12/31/2026
- Budget
- 1,268,745 EUR
Fundings
| Name | Role | Start | End | Amount |
|---|---|---|---|---|
| KLIMAFORSK - Large scale programme on Climate | Grant | - | - | 1,268,744 EUR |
Abstract
In the 20th century, emissions of ozone-depleting compounds caused a global environmental crisis through their ability to cause ozone depletion in the atmosphere. Ozone plays a vital role for life on Earth through providing a screening mechanism for dangerous solar UV-B radiation, which is known to have negative effects on plants and animals (including skin cancer in humans). Global environmental policy has been successful in reversing the trend in the emission of ozone-depleting atmospheric chemicals worldwide, so that exposure to dangerous UV-B radiation is likely to be less of a threat to ecosystems and humans in the 21st century. However, large variations in ozone and surface UV-B radiation have also thought to have occurred in the geological past with potentially major implications for climate and ecosystems. For example, swings in the Earth’s geomagnetic field may have caused changes in ozone concentrations, and the increases in solar UV-B radiation at the Earth’s surface that resulted have even contributed to the extinction of the Neanderthals. But although UV-B radiation is an important variable for understand process influencing life on Earth, at present it remains challenging to reconstruct changes in UV-B radiation at the Earth’s surface beyond the instrumental measurements since the 20th century. QUEST-UV will attempt to solve this challenge through the chemical analysis of fossil-pollen grains. Since the 2000s researchers have suggested that chemical sunscreens produced by plants, and which are also found in the walls of pollen grains and then buried in lakes and bogs over thousands of years, may be used to reconstruct UV-B radiation received at the Earth’s surface. QUEST-UV will use experiments to provide the experimental support for this proxy, and then use this understanding to provide the first quantitative reconstruction of UV-B radiation based on sediments representing up to the last 10,000 years.