Environment

Humanity
did not take the steps necessary to reduce anthropogenic climate change before
certain feedback loops kicked in – primarily the release of methane and CO2
from the soil and lowered planetary albedo. This has caused temperatures to
rise by an average of 4 degrees globally, and an average of 6 degrees over
major landmasses. The heat island effect means that major metropolitan areas
experience temperatures an average of 8 degrees hotter than in 1984.

The arctic
is ice-free in the summer. Sea levels have risen by a little over 1 metre,
killing or displacing hundreds of millions of people. Though the greatest
effects were felt in Asia, Miami, New York and Boston were all partially and
permanently inundated. Shanghai, Bangkok, Jakarta, Ho Chi Minh City, Shenzen,
Ghangzhou and Mumbai were flooded, undermined and ultimately drowned.

Coastal
flooding has been accompanied by drier inland temperatures. Drought has caused
the collapse of agriculture across 90% of the formerly most arable land.
Pastoral farming of cows, sheep and pigs has ended, with virtually all meat now
vat grown or printed. Chocolate and coffee, on account of their highly specific
and narrow growing areas, are luxury goods. Dust storms blanket inland cities
for months each year. Almost all land agriculture now takes place in Vertical
Farms – hydroponic, mass-produced Towers. Bushfires have torn through Northern
Africa, North America, Southern Europe, the Eurasian Steppes and Australia,
pushing populations towards the cities. Heatwaves kill millions every year.

The wild
changes to ocean and surface temperatures and precipitation have driven an
explosion in storm frequency and severity. Green Zone cities have been
redesigned to weather horrendous storms that would wipe 20th Century
cities off the map, while the same storms have killed tens or hundreds of
millions in Red Zone countries.

The oceans
are not only hotter, they are more acidic, with a pH of around 7.5, due to the
dissolution of CO2 from the atmosphere. This is coupled with oceanic ‘dead
zones’, where runoff and pollutants cause algal blooms that strip all oxygen
from a coastline, killing any fish within it. Waste is all-pervasive in the
seas, with microplastics present in every water system on earth. As a result,
wild aquaculture has collapsed; fish only live wild in the far north and far
south of the planet, while crustaceans are extinct in the wild. Whales are
extinct and coral only exists off the coast of Norway and Argentina. The only common
sea life is jellyfish and algae, both of which have thrived and are eaten by
the poor.

Land
animals have also suffered. Climate change and wildfire has destroyed habitats,
with jungles like the Amazon and the Congo nearly dead from heat stress. This has
driven to extinction nearly all large mammals and amphibians in the wild. Some
animals have thrived, including rats, ants, wasps, cockroaches, and locusts, as
well as flies. Pine beetles and mosquitoes have spread across the planet,
enabled by an extension to their habitat.

Air
quality is terrible everywhere. In the latter half of the century, the Green
Zones had largely transitioned to low-carbon energy and transport, but other
countries still generated massive pollutants and in the new tower cities, toxic
smog, particulate gases and exhaust had nowhere to go. The worst of it tends to
be trapped at the level of the Warrens by a layer of ozone. In the soil and
water, carcinogenic microparticles are rife, as are isotopes from the
Indian-Pakistani Nuclear War, along with heavy metals, preservatives,
antibiotics and microplastics.

Needless
to say, these environmental changes were suffered most by those who were poor;
worse, those areas

heaviest hit by climate change and its consequences tended
to be in the poorer, developing regions of the world. Quite literally billions
of people have been displaced in the last forty years, from Asia, Africa and
South America. Moving into neighbouring poor countries, these migrants often
overwhelmed struggling governments and caused further collapse like falling
dominoes. As the Green Zone countries faced a wave of climate migration unlike
anything they had ever conceived, they took increasingly authoritarian and
extreme measures to prevent these migrants reaching their shores.

 [As an aside, I chose this scenario because it
is in the middle range in terms of severity of all scenarios predicted to arise
from climate change assuming we take no or minimal action to limit it. There
are far better and far worse scenarios, but this is around the average now.
This is not an extreme – this is likely.]