Coral reefs are havens for marine biodiversity and underpin the economies of many coastal communities. But they are very sensitive to changes in ocean chemistry resulting from greenhouse gas emissions, as well as to pollution, warming waters, overdevelopment, and overfishing. Reefs use a mineral called aragonite, a naturally occurring form of calcium carbonate, CaCO3, to make their skeletons.  When carbon dioxide, CO2, from the atmosphere is absorbed by the ocean, it forms carbonic acid—the same stuff that makes soda fizz--making the ocean more acidic and thus more difficult for many marine organisms to grow their shells and skeletons and threatening coral reefs globally.

Ken Caldeira and colleagues have looked at several aspects of coral reef decline. In one study they calculated ocean chemical conditions that would occur under different future scenarios and determined that if we continue on our current emissions path, by the end of the century there will be no areas of the ocean with the chemical properties that have supported coral reef growth in the past. In another study at Australia’s Great Barrier Reef, the researchers found that carbonate accumulation is 44% lower than 40 years ago and that the reef  dissolves  nearly three times more at night than in the 1970s. They suspect that sea cucumbers are a factor in this nightly activity as they feed.


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March 17, 2020

The Carnegie Institution for Science is consolidating our California research departments into an expanded presence in Pasadena. With this move, we are building on our existing relationship with Caltech, with a goal of broadening our historic collaborations in astronomy and astrophysics and pursuing new opportunities in ecology and plant biology that will support the global fight against climate change.

This plan, which affects our research operations in Pasadena and Palo Alto, reflects Carnegie’s ongoing efforts to extend our leadership in space, Earth, and life sciences and to enhance our ability to explore new frontiers.

In selecting our Pasadena location, we

Downwelling field experiment at Searsville Reservoir. Courtesy Nona Chiariello.
March 2, 2020

Washington, DC— Could pumping oxygen-rich surface water into the depths of lakes, estuaries, and coastal ocean waters help ameliorate dangerous dead zones? New work led by Carnegie’s David Koweek and Ken Caldeira and published open access by Science of the Total Environment says yes, although they caution that further research would be needed to understand any possible side effects before implementing such an approach.

When excessive nutrients from agriculture and other human activities wash into waterways, it can create a dangerous phenomenon called eutrophication. This can lead to low-oxygen dead zones called hypoxia.

“Low-oxygen dead zones are one of

Land and air pollution in Amravati, India, purchased from Shutterstock.
February 17, 2020

Washington, DC— Aerosol emissions from burning coal and wood are dangerous to human health, but it turns out that by cooling the Earth they also diminish global economic inequality, according to a new study by Carnegie’s Yixuan Zheng, Geeta Persad, and Ken Caldeira, along with UC Irvine’s Steven Davis. Their findings are published by Nature Climate Change.

Tiny particles spewed into the atmosphere by human activity, called “anthropogenic aerosols,” interact with clouds and reflect some of the Sun’s energy back into space. They have a short-term cooling effect that’s similar to how particles from major volcanic eruptions can cause global

The sea anemone Aiptasia, photo by Ken Caldeira
November 12, 2019

Washington, DC— Bleached anemones—those lacking symbiotic algae—do not move toward light, a behaviour exhibited by healthy, symbiotic anemones. Published in Coral Reefs, this finding from Carnegie’s Shawna Foo, Arthur Grossman, and Ken Caldeira, along with Lauren Liddell of the NASA Ames Research Center, is a fascinating case study for exploring the concept of control in a symbiotic relationship.

Anemones are closely related to coral and can help scientists understand coral reef ecosystems. Like corals, they host algae that convert the Sun’s energy into food by a process called photosynthesis. The algae share some of the nutrients they produce with

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Anna Michalak’s team combined sampling and satellite-based observations of Lake Erie with computer simulations and determined that the 2011 record-breaking algal bloom in the lake was triggered by long-term agricultural practices coupled with extreme precipitation, followed by weak lake circulation and warm temperatures. The bloom began in the western region in mid-July and covered an area of 230 square miles (600 km2). At its peak in October, the bloom had expanded to over 1930 square miles (5000 km2). Its peak intensity was over 3 times greater than any other bloom on record. The scientists predicted that, unless agricultural policies change, the lake will continue to experience

Chris Field is a co-principal investigator of the Jasper Ridge Global Change Experiment at the Jasper Ridge Biological Preserve in northern California. The site, designed to exploit grasslands as models for understanding how ecosystems may respond to climate change, hosts a number of studies of the potential effects from elevated atmospheric carbon dioxide, elevated temperature, increased precipitation, and increased nitrogen deposition. The site houses experimental plots that replicate all possible combinations of the four treatments and additional sampling sites that control for the effects of project infrastructure. Studies focus on several integrated ecosystem responses to the

Until now, computer models have been the primary tool for estimating photosynthetic productivity on a global scale. They are based on estimating a measure for plant energy called gross primary production (GPP), which is the rate at which plants capture and store a unit of chemical energy as biomass over a specific time. Joe Berry was part of a team that took an entirely new approach by using satellite technology to measure light that is emitted by plant leaves as a byproduct of photosynthesis as shown by the artwork.

The plant produces fluorescent light when sunlight excites the photosynthetic pigment chlorophyll. Satellite instruments sense this fluorescence yielding a direct

In March 2014, a technical support unit (TSU) of ten, headquartered at Global Ecology, had successfully completed a herculean management effort for the 2000-page assessment Climate Change 2014: Impacts, Adaptation, and Vulnerability, including two summaries. They were issued by the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC), Working Group II co-chaired by Chris Field, Global Ecology director, with science co-directors Katie Mach and Mike Mastrandrea managing the input of over 190 governments and nearly 2,000 experts from around the world.

The IPCC, established in 1988, assesses information about climate change and its impacts. In September 2008, Field was

Brittany Belin joined the Department of Embryology staff in August 2020. Her Ph.D. research involved developing new tools for in vivo imaging of actin in cell nuclei. Actin is a major structural element in eukaryotic cells—cells with a nucleus and organelles —forming contractile polymers that drive muscle contraction, the migration of immune cells to  infection sites, and the movement of signals from one part of a cell to another. Using the tools developed in her Ph.D., Belin discovered a new role for actin in aiding the repair of DNA breaks in human cells caused by carcinogens, UV light, and other mutagens.

Belin changed course for her postdoctoral work, in

Evolutionary geneticist Moises Exposito-Alonso joined the Department of Plant Biology as a staff associate in September 2019. He investigates whether and how plants will evolve to keep pace with climate change by conducting large-scale ecological and genome sequencing experiments. He also develops computational methods to derive fundamental principles of evolution, such as how fast natural populations acquire new mutations and how past climates shaped continental-scale biodiversity patterns. His goal is to use these first principles and computational approaches to forecast evolutionary outcomes of populations under climate change to anticipate potential future

Staff Associate Kamena Kostova joined the Department of Embryology in November 2018. She studies ribosomes, the factory-like structures inside cells that produce proteins. Scientists have known about ribosome structure, function, and biogenesis for some time. But, a major unanswered question is how cells monitor the integrity of the ribosome itself. Problems with ribosomes have been associated with diseases including neurodegeneration and cancer. The Kostova lab investigates the fundamental question of how cells respond when their ribosomes break down using mass spectrometry, functional genomics methods, and CRISPR genome editing.

Kostova received a B.S. in Biology from the

Sally June Tracy applies cutting-edge experimental and analytical techniques to understand the fundamental physical behavior of materials at extreme conditions. She uses dynamic compression techniques with high-flux X-ray sources to probe the structural changes and phase transitions in materials at conditions that mimic impacts and the interiors of terrestrial and exoplanets. She is also an expert in nuclear resonant scattering and synchrotron X-ray diffraction. She uses these techniques to understand novel behavior at the electronic level.  Tracy received her Ph.D. from the California Institute of