Sammanfattning

Lakes and ponds are important natural sources of the potent greenhouse gas methane (CH4), with small shallow waters identified as particular hotspots(1,2). Ebullition (bubbles) of CH4 makes up a large proportion of total CH4 flux(3,4). However, difficulty measuring such episodic events(5) makes prediction of how ebullition responds to nutrient enrichment and rising temperatures challenging. Here, the world's longest running, mesocosm-based, shallow lake climate change experiment was used to investigate how the combination of warming and eutrophication (that is, nutrient enrichment) affects CH4 ebullition. Eutrophication without heating increased the relative contribution of ebullition from 51% to 75%. More strikingly the combination of nutrient enrichment and experimental warming treatments of +2-3 degrees C and +4-5 degrees C had a synergistic effect, increasing mean annual ebullition by at least 1900 mg CH4-C m(-2) yr(-1). In contrast, diffusive flux showed no response to eutrophication and only a small increase at higher temperatures (average 63 mg CH4-C m(-2) yr(-1)). As shallow lakes are the most common lake type globally, abundant in highly climate sensitive regions(6) and most vulnerable to eutrophication, these results suggest their current and future contributions to atmospheric CH4 concentrations may be significantly underestimated.

Publicerad i

Nature Climate Change
2018, Volym: 8, nummer: 2, sidor: 156-160
Utgivare: NATURE PUBLISHING GROUP

SLU författare

• Audet, Joachim

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    
  • Aarhus Universitet

Globala målen

Vidta omedelbara åtgärder för att bekämpa klimatförändringarna och dess konsekvenser


UKÄ forskningsämne

Klimatforskning


Publikationens identifierare

DOI: https://doi.org/10.1038/s41558-017-0063-z

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/93844