Mexico City is drinking itself into the ground

Mexico City's cathedral, which had to be propped up with stone wedges as it was being built to stop it sinking. Image: Francisco Diez

When the Aztecs founded the city of Tenochtitlán in the middle of a lake, they thought they were being incredibly clever.

It was 1325, the height of the era of Mesoamerican tribes vying for supremacy in the narrowing strip between the Pacific Ocean and the Caribbean Gulf, and a small island on the western side of Lake Texcoco seemed like a pretty good place to be. 

The Mexica people who lived there – and from whose tribe the name Mexico now comes – became enormously successful. Their Aztec Empire was the most formidable force on the continent, exerted control and influence for thousands of miles around, and established trading relationships stretching as far as the Inca Empire in modern-day Peru.

Their island city, smattered with canals, causeways, and dykes, was a lesson in sustainability.

Lake Texcoco and the city of Tenochtitlán before s*** went down. Image: Yavidaxiu.

The channels they built provided natural irrigation and water management, while floating gardens called chinampas kept the city fed as it grew to an astonishing size. By the time the Spanish conquistadores arrived in the 16th century, the city had approximately 300,000 residents – making it five times the size of London at the time.

The Mexico City of today is a very different story.

A choked-up Mexico City today. Image: Fidel Gonzalez/creative commons.

Up no creek with no canoe

A choking, smog-shrouded sprawl of 21m people. It has no island, no lake, a water shortage that means millions are left with empty taps on a regular basis, and is sinking at an astonishing rate.

Roughly 20 per cent of Mexico City’s residents cannot guarantee that water will come out of their taps every day, and the ground is sinking by as much as nine inches a year in some suburbs. That’s the equivalent of nearly a storey a decade.

The city’s cathedral, which took more than 200 years to build, has a leaning chapel and bell tower, propped up by stone wedges to stop the whole thing crumbling down. The Gilded Angel of Independence – a local tourist hotspot and national landmark – was built with nine shallow steps leading up from the street below. As the surrounding area has sunk, an extra 14 large steps have been added as the angel is increasingly left marooned above a vanishing city.

Slanted buildings leer menacingly over pavements, their doors and windows no longer in alignment with their friends as if crudely displaced from a grotesque theme park funhouse. Terraced streets built on level ground now undulate, with wavy gables crowding up against each other in parts, and pulling away in others, while city-dwellers struggle up hilly pavements where once the path was flat.

In Iztapalapa, a suburb of approximately 2m people built on the ancient lake’s southern shores in the city’s south-east, 15 primary schools have crumbled or caved in, and a teenager was swallowed up when a gaping crack appeared in the street.

So what happened?

As per usual, the blame can be placed squarely on the shoulders of the pesky European invaders.

Xochimilco, the last vestige of Mexico City's lakeside history. Image: Owen Prior.

Veni, vidi, conquistadori

When Hernán Cortes entered the city in 1519, he was “stunned by its beauty and its size”, and in awe of a city where he was welcomed as a god and given plush lodgings by the Aztecs. This, obviously, did not last: war ensued, and the conquistadores took control of the city and named it the capital of their new colony, the Viceroyalty of New Spain.

Where the Aztecs had constructed dykes and channels to live in harmony with the lake, the Spaniards covered them over to build roads and increase the city’s size. They started draining the lake and cutting down the forests on its shores, making the city more susceptible to intense flooding.

Mexico City suffered major floods in 1555, 1580, 1604, and 1607, before one bright spark proposed moving the capital to dry land in 1630. But after deliberating on this for a while, the authorities decided that the answer was no, and the flooding continued, with more serious deluges in 1645, 1674, 1691, 1707, 1714, 1724, 1747, and 1763.

One flood was so severe that the entire city was submerged for five whole years from 1629 – yet the city lived on, gasping for air and expanding further across the lakebed between downpours.

By the 20th century, most of the lake had been drained, and flooding became the least of the city’s worries. As it grew and grew, and poorer migrants from the surrounding country arrived in search of economic opportunity, Mexico City grew thirsty.

Which was a problem.

The Gilded Angel of Independence, which has risen above the sinking streets. Image: TJ DeGroat.

Geologically insane

The city is built on two different geological foundations. Some of the ground underneath Mexico City is volcanic soil, which was fertile and used by the Aztecs for growing crops. It was also handily water-absorbent: moisture would soak in and flow to underground aquifers easily, without damaging the structure of the soil.

But when developers built on the volcanic soil and covered it in concrete and asphalt, water could no longer get through to the soil and filter through to the aquifers on which the city relies. And other parts of the city sit on clay. This, unlike the volcanic soil, can't absorb the water, merely sandwiching it between layers of clay – like cream between layers of pastry. When the cream is sucked out, the layers of pastry crack and collapse, falling on top of one another.


And that’s what’s happened beneath Mexico City. Desperate for water in a lake basin devoid of a lake, the city has tapped into the clay soil while covering over the useful volcanic soil. And as the city is built on a mixture of both geologies, it has sunk in an uneven, mismatched way, causing dangerous fissures, cracks, and the bizarre phenomenon of wavy, undulating streets.

It is estimated that the city has dropped 10 meters in the last century; if anything the signs are that this process is accelerating.

The climate change doom blockbusters show us coastal cities dramatically engulfed by storms and waves from rising sea levels, as great ice shelves melt in the Arctic and Antarctic.

But one of the first cities claimed as victims by man-made destruction may be less cinematic: a leviathan of 21m sinking into the ground, cracking and buckling, swallowing up people, houses, and livelihoods, and starving its poorest residents of water and hope as it goes. 

Jack May is a regular contributor to CityMetric and tweets as @JackO_May.

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Seven climate change myths put about by big oil companies

Oil is good for you! Image: Getty.

Since the start of this year, major players within the fossil fuel industry – “big oil” – have made some big announcements regarding climate change. BP revealed plans to reduce its greenhouse gas emissions by acquiring additional renewable energy companies. Royal Dutch Shell defended its $1-$2bn green energy annual budget. Even ExxonMobil, until recently relatively dismissive of the basic science behind climate change, included a section dedicated to reducing emissions in its yearly outlook for energy report.

But this idea of a “green” oil company producing “clean” fossil fuels is one that I would call a dangerous myth. Such myths obscure the irreconcilability between burning fossil fuels and environmental protection – yet they continue to be perpetuated to the detriment of our planet.

Myth 1: Climate change can be solved with the same thinking that created it

Measures put in place now to address climate change must be sustainable in the long run. A hasty, sticking plaster approach based on quick fixes and repurposed ideas will not suffice.

Yet this is precisely what some fossil fuel companies intend to do. To address climate change, major oil and gas companies are mostly doing what they have historically excelled at – more technology, more efficiency, and producing more fossil fuels.

But like the irresponsible gambler that cannot stop doubling down during a losing streak, the industry’s bet on more, more, more only means more ecological destruction. Irrespective of how efficient fossil fuel production becomes, that the industry’s core product can be 100 per cent environmentally sustainable is an illusion.

A potential glimmer of hope is carbon capture and storage (CCS), a process that sucks carbon out of the air and sends it back underground. But despite being praised by big oil as a silver bullet solution for climate change, CCS is yet another sticking plaster approach. Even CCS advocates suggest that it cannot currently be employed on a global, mass scale.

Myth 2: Climate change won’t spell the end of the fossil fuel industry

According to a recent report, climate change is one factor among several that has resulted in the end of big oil’s golden years – a time when oil was plenty, money quick, and the men at the top celebrated as cowboy capitalists.

Now, to ensure we do not surpass the dangerous 2°C threshold, we must realise that there is simply no place for “producers” of fossil fuels. After all, as scientists, financial experts, and activists have warned, if we want to avoid dangerous climate change, the proven reserves of the world’s biggest fossil fuel companies cannot be consumed.

Myth 3: Renewables investment means oil companies are seriously tackling climate change

Compared to overall capital expenditures, oil companies renewables’ investment is a miniscule drop in the barrel. Even then, as companies such as BP have demonstrated before, they will divest from renewables as soon as market conditions change.

Big oil companies’ green investments only produce tiny reductions in their overall greenhouse gas emissions. BP calls these effects “real sustainable reductions” – but they accounted for only 0.3 per cent of their total emissions reductions in 2016, 0.1 per cent in 2015, 0.1 per cent in 2014, and so on.


Myth 4: Hard climate regulation is not an option

One of the oil industry’s biggest fears regarding climate change is regulation. It is of such importance that BP recently hinted at big oil’s exodus from the EU if climate regulation took effect. Let’s be clear, we are talking about “command-and-control” regulation here, such as pollution limits, and not business-friendly tools such as carbon pricing or market-based quota systems.

There are many commercial reasons why the fossil fuel industry would prefer the latter over the former. Notably, regulation may result in a direct impact on the bottom line of fossil fuel companies given incurred costs. But climate regulation is – in combination with market-based mechanisms – required to address climate change. This is a widely accepted proposition advocated by mainstream economists, NGOs and most governments.

Myth 5: Without cheap fossil fuels, the developing world will stop

Total’s ex-CEO, the late Christoph de Margerie, once remarked: “Without access to energy, there is no development.” Although this is probably true, that this energy must come from fossil fuels is not. Consider, for example, how for 300 days last year Costa Rica relied entirely on renewable energy for its electricity needs. Even China, the world’s biggest polluter, is simultaneously the biggest investor in domestic renewables projects.

As the World Bank has highlighted, in contrast to big oil’s claims about producing more fossil fuels to end poverty, the sad truth is that by burning even the current fossil fuel stockpile, climate change will place millions of people back into poverty. The UN concurs, signalling that climate change will result in reduced crop yields, more waterborne diseases, higher food prices and greater civil unrest in developing parts of the world.

Myth 6: Big oil must be involved in climate policy-making

Fossil fuel companies insist that their involvement in climate policy-making is necessary, so much so that they have become part of the wallpaper at international environmental conferences. This neglects that fossil fuels are, in fact, a pretty large part of the problem. Big oil attends international environmental conferences for two reasons: lobbying and self-promotion.

Some UN organisations already recognise the risk of corporations hijacking the policy-making process. The World Health Organisation, for instance, forbids the tobacco industry from attending its conferences. The UN’s climate change arm, the UNFCCC, should take note.

Myth 7: Nature can and must be “tamed” to address climate change

If you mess with mother nature, she bites back. As scientists reiterate, natural systems are complex, unpredictable, and even hostile when disrupted.

Climate change is a prime example. Small changes in the chemical makeup of the atmosphere may have drastic implications for Earth’s inhabitants.

The ConversationFossil fuel companies reject that natural systems are fragile – as evidenced by their expansive operations in ecologically vulnerable areas such as the Arctic. The “wild” aspect of nature is considered something to be controlled and dominated. This myth merely serves as a way to boost egos. As independent scientist James Lovelock wrote, “The idea that humans are yet intelligent enough to serve as stewards of the Earth is among the most hubristic ever.”

George Ferns, Lecturer in Management, Employment and Organisation, Cardiff University.

This article was originally published on The Conversation. Read the original article.