Mangroves are many species of tree adapted to living in salty water along coastlines and tidal rivers not far from the equator. They are remarkable in many ways and confer a host of benefits to their habitats. Here are some significant ones.

Mangroves and mangrove habitats play a major role in protecting coastal settlements from storm surges and waves. Mangroves significantly reduce the energy of waves, lowering wave height inland, including from tsunamis, and reduce surges from tropical storms. We took a boat through the mangroves in Southern Vietnam once, and it was an eye-opening maze of channels and islands. I could see how they act like a natural breakwater.

Mangroves help stabilise land from erosion. This helps plants and fauna inland make their homes. Mangrove root systems also trap sediment brought downriver or from the sea, building their environment and creating peaty soil when they decay.

Their incredible prop root network creates a wonderful sheltered space for marine wildlife to grow and develop. The nooks and crannies help protect young from predators until they are older and can better fend for themselves. This protective environment increases populations and helps local fishers and communities. The calm and sheltered waters inside mangrove habitats also provide sanctuary for birds and a host of other non-marine wildlife.

Mangroves are an excellent carbon sink. They capture carbon as they grow, and the low-oxygen sediments deposited beneath them help lock carbon away.

I've contributed to plant trees through Eden Projects with a portion of any monthly or one-off support I receive. I wanted to explain Mangroves partly because, as of July 2023, together, we've passed 26,000 trees planted, most in mangrove restoration projects in Madagascar, and provided over 350 work days for locals.

"Madagascar is one of the world's top biodiversity conservation priorities because of its endemic species and severe habitat loss rates. Restoration in Madagascar is important because the destruction of the mangrove estuaries along the coastline has caused mudflats to wash into the ocean, destroying once-productive fisheries and increasing the vulnerability of coastal communities to hurricanes, tsunamis, and floods. In the dry deciduous forests, deforestation threatens one of the world's rarest and most diverse forest systems."

Mangroves make a real difference. To everyone who's helped make this happen, thank you!

Mangroves

Heat islands are urban areas that can have higher temperatures than surrounding rural areas with more greenery.

Heat islands are caused by several factors, including:

the types of materials we use in cities for buildings, pavement, and roads that can absorb more heat than natural surfaces such as leaves or grass

human additions to the sun's heat, such as air conditioning, vehicles, cooking, or machinery

the shapes of our cities that may restrict airflow to carry heat away

the mass of our buildings that can absorb heat and release it gradually, even through the night

More natural, often rural areas with greenery may reflect more light, release moisture and provide shade.

There are ways to help reduce the effect of heat islands, such as planting more urban trees or using green roofs.

Deciduous trees have the handy feature of providing shade for a house in the summer while letting light through in the winter when the leaves fall.

A study using 2015 data found that "doubling tree cover in European cities could cut the number of heat-related deaths during summer months by nearly 40 per cent." In Columbia's Medellín, creating 30 Green Corridors helped to reduce temperatures by 2°C in the first three years of the program.

Learn more about the heat island effect on the EPA site.

Heat islands

Climate anxiety is the background stress and dread caused by thinking about the state of the climate of the planet and where it's going.

While talking on a walk with our 9-year-old, he suddenly said, "Well, what does it matter anyway? We've messed up our planet and it's filling up with plastic." This is a mighty burden to bear for a 9-year old. With increased awareness and education across society, climate anxiety is real.

One good thing, however, is that one way to alleviate climate anxiety is to be taking action, and fortunately action is also what the planet needs, too.

One small action I take is a commitment to plant 5 trees each month with Eden: People+Planet for every person who supports me on Patreon at any financial level. A small contribution could also see you plant 60 trees a year. Together, I think we can make a difference.

Support me on Patreon and plant trees too.

Climate anxiety

Perhaps the most important curve of our times, Charles Keeling’s  curve shows the change in concentration of CO2 in the air with measurements taken every year for over 60 years. Taken at the top of Mauna Loa volcano in Hawaii because of its high altitude and relative isolation in the Pacific, Charles Keeling’s measurements show that the monthly average CO2 concentration in the air has risen from around 310 ppm (parts per million) to around 410 ppm in 2020. As a greenhouse gas this change in CO2 concentration is one of the critical causes of climate change.

The concentration varies seasonally as plants bloom in Spring and Summer reducing the concentration from its high around May as the CO2 has built up over the Norhern Hemisphere Winter.

The Scripps CO2 program is now overseen by Charles’ son Ralph Keeling.

The Keeling curve

If weather is like the money in your pocket on any one day, climate is like your net financial worth over time.

I liked this simple analogy to distinguish between weather and climate in a New York Times article by Kendra Pierre-Louis. While there are many causes of extreme weather, keeping this analogy in mind helps keep some overall context even when you’re in the midst of an unexpected cold snap.

Weather and climate: an analogy

Jared Diamond’s classic book Guns, Germs and Steel, proposes some remarkable hypotheses about how the pattern of history played out, notably trying to answer the question of why it was generally the Europeans that invaded much of the rest of the world rather than the other way around. One hypothesis, striking in its simplicity if you’ve ever looked at a world map, is the significant contribution of the general orientation of the major continents.

The Americas are largely lined up north–south, while Europe and Asia (Eurasia) are largely lined up east-west. An east-west alignment means the land generally has a more similar climate, day-length and seasonal variations. The general logic of the hypothesis is that the similar latitude of an east–west alignment means animals, crops, as well as travel and trade, more easily spread across the continents than across those with a north–south alignment — of the Americas and Africa — which naturally encounter more different climatic zones.

As a simplified example, horses and other large animals and crops spread throughout the shared temperate latitudes of Eurasia. In contrast, South America’s only large domesticated animal, the thick-coated llama (and related species like the alpaca), couldn’t easily spread to North America through the impassable tropical barrier of the isthmus of Panama. They just aren’t built for it.

There are a lot of viewpoints on the theory, and Diamond includes many more factors of geography and others — like never being able to domesticate the zebra — that go towards answering his question of why Spain invaded the Americas and not vice-versa. But ever since reading his simple hypothesis, available to anyone with a world map, I’ve found it hugely intriguing.

Climate sketches