Blooms at Lower pH Levels Could Upset Ocean’s Acidification Cycle

by Max Breitbarth

Ocean acidification—the absorption of atmospheric CO2 by the ocean—has increased due to anthropogenic emissions of CO2, resulting in growing concentrations of CO2 in our oceans. Flynn et al. (2015) created models based on projections of increasing ocean acidity to explore the effects of algae blooms at decreasing pH levels and the effects of these blooms on phytoplankton populations that keep the ocean’s acidity within a manageable spectrum. Continue reading

How a Crucial Tropical Forest is Responding to Climate Change

by Pushan Hinduja

How are Mangrove forests throughout tropical areas of the world responding to the rising sea levels attributed to climate change? Daniel M. Alongi, of the Australian Institute of Marine Sciences, analyzed historic responses to changes in sea levels in Mangrove forests as well as current data to determine how well these forests are reacting to the climate crisis (Alongi 2015). Mangrove forests tend to occupy the border between land and sea in low latitudes, making them especially susceptible to the effects of climate change. Fortunately for mangroves, they have an outstanding ecological stability, in part due to their large subterranean storage capabilities. However, despite responses to develop resilience to environmental disturbances, mangrove forests are still suffering. In terms of human impact, mangrove forests are being deforested at a rate of 1-2% per year, leaving only about a century before these forests disappear entirely. Mangroves are crucial to the environment; they serve as breeding and nursery grounds for fish, birds and other animals, prevent erosion and damage from natural disasters like tsunamis, serve as a renewable source of wood for fuel, and are key components in filtering ocean contaminants. Continue reading

Socio-Economic Status and Climate Change

by Patrick Quarberg

The agricultural response to climate change will greatly affect how the world adapts to different environmental conditions. Given that crops respond differently to differently levels of CO2 in the atmosphere, it is important that agricultural developments are made to be able to cope with changing crop yields. A less thought of effect of climate change is how socio-economic factors influence how food is grown and distributed, as well as how different areas are able to respond to a shifting global climate. Studies on how crops respond to increased CO in the atmosphere have revealed some positive effects on growth and water retention. Using this information, Parry et al. set out to investigate how these changes affected places of different socio-economic status. Continue reading

Is the Government Accountable for Climate Change?

by Abby Schantz

In “Oregon teens sue state: Can local government be held accountable for climate change?” Samantha Laine tells the story of two teenagers who are attempting to sue the government for not protecting its people from climate change. Three years ago, Kelsey Juliana and Olivia Chernaik, at the ages of 14 and 11 respectively, filed a lawsuit in the Lane County Circuit Court. Juliana and Chernaik argued that the state of Oregon was violating the public trust doctrine by not working to mitigate climate change rapidly. House Bill 3542, which was introduced 8 years ago and set carbon emission reduction goals, was unaccomplished. The teens argued that just as the government protects forests, oceans, and other natural resources, it is the state’s responsibility to protect the atmosphere. Continue reading

The Economic Value of Coral Reefs

by Kimberly Coombs

Coral reefs are known for supporting a habitat rich in species diversity and abundance. Besides the benefit coral reefs provide to other species, they also offer a benefit to humans. Coral reefs provide a source of economic gain in terms of tourism and fisheries, usually bringing in about $30 billion each year. However, climate change is threatening to diminish this revenue as corals become bleached and experience higher rates of mortality.

Chen et al. (2015) conducted a study to estimate the global economic impact from loss of corals as a result of climate change. They identified three main factors from climate change that impact coral reefs the most: sea surface temperatures, CO2 concentrations in the water, and sea level rise. In order to assess the impact of these factors on coral reefs, Chen et al. used a threshold model in which they found that there are two temperature thresholds that may negatively impact coral reefs. When sea surface temperatures are between 22.37 and 26.85, coral cover may increase; conversely, when sea surface temperatures drop below 22.37 or rise above 26.85, coral cover decreases. Chen et al. found that increasing CO2 concentrations also cause a decrease in coral cover, while sea level fluctuations were found to have no significant effect.

In order to evaluate the value of coral reefs, Chen et al. used a meta-analysis that incorporated the percent coral cover, number of visitors to the reefs, GDP per capita, and the tourism expenditure for each visitor. They found that when coral cover decreased, reef value was reduced. The number of visitors correlates negatively with coral reef value because visitors prefer to visit uncrowded coral reefs. The GDP per capita and the tourism expenditure for each visitor were found to have positive effects on coral reef value.

Lastly, Chen et al. developed four different mitigation scenarios in response to climate change to evaluate coral reef value. The impact of these different mitigation scenarios on tourism and recreation revenue varies as coral cover varies under these scenarios. The economic loss ranges from $1.88 billion to $12.02 billion by the year 2100. Chen et al. noted that this result only represents the coral reef value from tourism and recreation and that there are many other factors that will be impacted by a decline in coral cover; therefore, they create a crude economic loss estimate under these four mitigation scenarios that ranges from $3.72 billion to $23.78 billion.

Overall, CO2 and sea surface temperatures will affect coral cover, which will reduce the coral reef value. A reduction in coral reef value reduces the recreation and tourism expenditures amongst other factors; therefore, ensuring coral cover remains high will give a higher guarantee that recreation, tourism.

Chen, P., Chen, C., Chu, L., McCarl, B., 2015. Evaluating the economic damage of climate change on global coral reefs. Global Environmental Change, 30, 12-20.

Modeling CO2 and CH4 Fluxes in the Arctic using Satellite data

by Rebecca Herrera

The peatlands and tundras of the Arctic perform vital ecosystem services to the earth through their ability to sequester carbon (CO2) and methane (CH4) and function as a carbon sink. The ability of the permafrost in the peatlands and tundra ecosystems of the Arctic to continue to function as a natural reservoir for carbon and methane may be disrupted by rising global temperatures that increase the rate of soil decomposition. Watts et al. (2014) integrate a terrestrial carbon flux (TCF) model to include a newly developed CH4 emissions algorithm. The new TCF model simultaneously assesses CO2 and CH4 fluctuations and the corresponding net ecosystem carbon balance (NECB), which is contingent upon gross primary productivity (GPP) subtracted from ecosystem respiration. The integrated TCF model uses data gathered through satellite remote sensors to assess fluxes in CO2 and CH4. Continue reading