Our planet is getting warmer! Here in the Philippines, we are experiencing hot weather that seems unbearable. It wasn’t this way before but we cannot deny that this year’s summer is hotter compared to last year. And it’s not getting better as the El Niño phenomenon is fast approaching.
I’m no expert on the matter, so allow me present some facts from the reliable pundits. So, you cannot surmise that what I am telling you here is just tittle-tattle. After all, as the saying goes, truth is stranger than fiction!
The average global temperature on Earth has increased by at least 1.1°C since 1880, according to the US National Aeronautics and Space Administration (NASA). The majority of the warming has occurred since 1975, at a rate of roughly 0.15°C to 0.20°C per decade.
“Every heatwave that we are experiencing today has been made hotter and more frequent because of climate change,” said Friederike Otto, a climate scientist at Imperial College London who also co-leads the World Weather Attribution research collaboration.
Extra greenhouse gases (GHGs) – like carbon dioxide and methane – in our atmosphere are the chief reason that Earth gets warmer. It’s alright to have these GHGs in our atmosphere as they help our planet warm enough to live on.
But excessive GHGs can cause too much warming. Just like what happens on Venus, where excessive greenhouse effect has elevated temperatures to extreme levels. And we don’t want that to happen to Earth.
To stop this from happening, experts say we need to lessen the emission of GHGs, particularly carbon dioxide, into the atmosphere. Or, sequester the swelling carbon dioxide now inhabiting our atmosphere.
More often than not, when you hear the words “carbon sequestration,” we often think of tropical rainforests. Unknowingly, oceans, marine plants and coastal ecosystems also play a vital role in removing carbon dioxide from our atmosphere and storing it as organic carbon.
This idea led to the creation of “blue carbon.” Coined in 2009, it draws attention to the degradation of marine and coastal ecosystems and the need to conserve and restore them to mitigate climate change and for the other ecosystem services they provide.
The Nobel-prize winning Intergovernmental Panel on Climate Change (IPCC) defines blue carbon in these words: “All biologically-driven carbon fluxes and storage in marine systems that are amenable to management.”
This refers to those rooted vegetation in the coastal zone, such as mangroves and seagrasses.
“These ecosystems sequester and store more carbon – often referred to as ‘blue carbon’ – per unit area than terrestrial forests,” explained the International Union for the Conservation of Nature (IUCN). “The ability of these vegetated ecosystems to remove carbon dioxide from the atmosphere makes them significant net carbon sinks, and they are now being recognized for their role in mitigating climate change.”
If you are still having trouble understanding what blue carbon is all about, allow me to introduce Russell Christine B. Corcino of the Institute of Biology, College of Science at the University of the Philippines-Diliman.
“Human beings exhale carbon dioxide and this exhaled carbon is being ‘inhaled’ by plants,” she explained. “Once inhaled, they use the carbon to make food and plant parts (leaves, stems, etc.), thus storing the carbon in their plant parts. They can also store it in the soil once they die or when plant parts fall off and get buried in the soil. The soil stores higher carbon than the plant parts.”
Seagrass meadows and mangrove forests have natural capacity to sequester and store enormous amounts of so-called “blue carbon” in their sediments.
“As carbon sinks, they are a cheap and readily available natural resource useful in mitigating the negative impacts of climate change,” said the late Dr. Miguel D. Fortes, a marine scientist and author of several books and technical articles in refereed journals.
Mangroves and seagrasses can store or capture more than twice – or even four to five times than those forests growing in the uplands. As such, they largely contribute to “our goal of decreasing carbon dioxide in the atmosphere.” In simpler terms, they mitigate climate change and global warming.
Corcino is the lead author of the study, “Status, limitations, and challenges of blue caron studies in the Philippines: A bibliographic analysis.” Her four co-authors were Maria Elisa B. Gerona-Daga, Shaina C. Zamoza, John Kenneth R. Fraga, and Severino G. Salmo III.
Mangrove and seagrass ecosystems have been studied since the 1970s but only recently on its carbon storage capacity. “From our study, we computed that the amount of carbon stored in the country’s existing mangroves and seagrasses alone is around 80,000 times more than our carbon reduction commitments to the United Nations,” Corcino explained in an exclusive interview.
They found out that the carbon storage rate of Philippine mangroves is at 400 Megagram per hectare (Mg/ha), while that of seagrasses is at 80 Mg/ha. “This rate is around half of the average global carbon storage rate,” she said, but added that the estimates were based on very few data points.
Despite their importance, they are among the most threatened ecosystems on Earth. They are being degraded or destroyed at four times the rate of tropical forests.
If these mangroves and seagrasses disappear, “their carbon sink capacity is lost or adversely affected, and the carbon stored is released, resulting in emissions of carbon dioxide that contribute to climate change,” the IUCN warned.
Healthy blue carbon ecosystems, by the way, also “provide habitat for marine species, support fish stocks and food security, sustain coastal communities and livelihoods, filter water flowing into our oceans and reef systems, and protect coasts from erosion and storm surges,” reminds the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization.
