La Administración De Los Recursos Naturales

INVITED PAPER

The Anthropocene: From Global Change to Planetary

Stewardship

Will Steffen, A ° sa Persson, Lisa Deutsch, Jan Zalasiewicz, Mark Williams, Katherine Richardson,

Carole Crumley, Paul Crutzen, Carl Folke, Line Gordon, Mario Molina, Veerabhadran Ramanathan,

Johan Rockstro¨m, Marten Scheffer, Hans Joachim Schellnhuber, Uno Svedin

Received: 29 June 2011 / Accepted: 29 June 2011

Abstract Over the past century, the total material wealth

of humanity has been enhanced. However, in the twentyfirst

century, we face scarcity in critical resources, the

degradation of ecosystem services, and the erosion of the

planet’s capability to absorb our wastes. Equity issues

remain stubbornly difficult to solve. This situation is novel

in its speed, its global scale and its threat to the resilience

of the Earth System. The advent of the Anthropence, the

time interval in which human activities now rival global

geophysical processes, suggests that we need to fundamentally

alter our relationship with the planet we inhabit.

Many approaches could be adopted, ranging from geoengineering

solutions that purposefully manipulate parts of

the Earth System to becoming active stewards of our own

life support system. The Anthropocene is a reminder that

the Holocene, during which complex human societies have

developed, has been a stable, accommodating environment

and is the only state of the Earth System that we know for

sure can support contemporary society. The need to

achieve effective planetary stewardship is urgent. As we go

further into the Anthropocene, we risk driving the Earth

System onto a trajectory toward more hostile states from

which we cannot easily return.

Keywords Earth System  Anthropocence 

Planetary stewardship  Ecosystem services  Resilience

PEOPLE AND THE PLANET: HUMANITY

AT A CROSSROADS IN THE TWENTY-FIRST

CENTURY

The twin challenges of ‘‘peak oil’’—decreasing petroleum

resources and increasing demand—and climate change are

redefining the pathways of human development in the

twenty-first century (Sorrell et al. 2009; ASPO 2010;

Richardson et al. 2011). Less well known is the potential

shortage of the mineral phosphorus and the increasing

competition for land—sometimes referred to as the ‘‘land

grab’’ in relation to Africa—as the new economic giants of

Asia move to secure food resources in non-Asian territories.

The pathways of development followed by today’s

wealthy countries after the Second World War—built on

plentiful, cheap fossil fuel energy resources, an abundance

of other material resources, and large expanses of productive

land to be developed—cannot be followed by the

75–80% of the human population who are now at various

stages of their trajectories out of poverty, and are beginning

to compete with today’s wealthy countries for increasingly

scarce resources.

A large fraction of our population of nearly 7000 million

people needs more access to food, water and energy to

improve their material standard of living, and the prospect

of an additional 2000 million by 2050 intensifies the need

for basic resources. These challenges come at a time when

the global environment shows clear signs of deterioration

and, as a consequence, questions the continuing ability of

the planet to provide the same accommodating environment

that has facilitated human development over the past

10 000 years.

Climate change is a prominent sign of human-driven

changes to the global environment. The evidence that the

Earth is warming is unequivocal, and human emissions of

greenhouse gases, most importantly carbon dioxide (CO2),

have been responsible for most of the warming since the

middle of the twentieth century (IPCC 2007). The manmade

greenhouse gases have already trapped enough

infrared energy to warm the planet by more than 2C

(Ramanathan and Feng 2008). Although many uncertainties

still surround the risks associated with climate change,

 Royal Swedish Academy of Sciences 2011

www.kva.se/en 123

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DOI 10.1007/s13280-011-0185-x

impacts are already observable at today’s mean global

surface temperature rise of about 0.8C since the midnineteenth

century. These risks, such as those associated

with sea-level rise, extreme events, and shifts in rainfall

patterns, rise sharply as the temperature climbs toward 2C

above pre-industrial and quite possibly beyond (Richardson

et al. 2011).

At least as disturbing as climate change, and far less

well known and understood, is the erosion over the past

two centuries of ecosystem services, those benefits derived

from ecosystems that support and enhance human wellbeing.

The Millennium Ecosystem Assessment (MA 2005)

assessed 24 ecosystems services, from direct services such

as food provision to more indirect services such as ecological

control of pests and diseases, and found that 15 of

them are being degraded or used unsustainably. Humanity

now acquires more than the ongoing productivity of

Earth’s ecosystems can provide sustainably, and is thus

living off the Earth’s natural capital in addition to its

productivity. This can lead to continued improvements to

human well-being for some time, but cannot be sustained

indefinitely.

The challenges of peak oil, peak phosphorus (where the

demand for phosphorus may soon outstrip supply; Cordell

et al. 2009; Sverdrup and Ragnarsdottir 2011) and climate

change demonstrate the existence of limits to the rate or

magnitude at which humanity can consume the planet’s

geophysical resources. Furthermore, climate change and

the appearance of the ozone hole owing to man-made

chemicals are strong evidence that humanity can overwhelm

important chemical, physical, and biological processes

that modulate the functioning of the Earth System.

These unintended consequences on the global life support

system that underpins the rapidly expanding human

enterprise lie at the heart of the interconnected twenty-first

century challenges.

The classification system developed to define ecosystem

services (MA 2005) might be extended to include geophysical

goods and services and expanded to the scale of

the planet as a whole. These could be called Earth System

goods and services. The classification, based on three of the

four ecosystem services of the MA (2005), would include

the following types.

Provisioning goods and services: Most commonly

known as ‘‘resources’’, these include the well-known ecosystem

services of food, fiber, and fresh water (natural

resources), but would now also include fossil fuels, phosphorus,

metals, and other materials derived from Earth’s

geological resources. Many, but far from all, of these types

of goods and services have market prices, which can regulate

supply and demand to some extent.

Supporting services: In the ecosystem framework, these

include nutrient cycling, soil formation and primary

production. All are necessary to support, for example, wellfunctioning

agricultural systems. They are also sometimes

called ‘‘environmental resources’’. Geophysical processes

also provide supporting services that indirectly yield benefits

for humanity. Examples include the long-term provision

of fertile soils through glacial action, the upwelling

branches of ocean circulation that bring nutrients from the

deep ocean to support many of the marine ecosystems that

provide protein-rich food, and the Himalayan glaciers that

act as giant water storage facilities for the provision of

water resources.

Regulating services: Two of the most well known of

these are the ecological control of pests and diseases and

regulation of the climate system through the uptake and

storage of carbon by ecosystems. These regulating services,

also sometimes considered environmental resources, help

maintain an environment conducive for human life, rather

than directly contributing to provisioning goods and services.

Storage of carbon by ecosystems is a part of a larger,

Earth System regulatory service that has a significant

geophysical component—the dissolution of atmospheric

CO2 into the ocean. Other Earth System services include

the set of chemical reactions in the stratosphere that continually

form ozone, essential for filtering out biologically

damaging ultraviolet radiation from the sun, and the role of

the large polar ice sheets in regulating temperature. Regulating

services are generally considered as ‘‘free services’’

provided by nature.

The accelerating pressures on all three types of Earth

System goods and services that connect people and the

planet are coming together in the first decades

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