[Mike]

During our Regenerate Cascadia tour, Joe Brewer addressed “The Nine Planetary Boundaries”. The concept of the Nine Planetary Boundaries was established by a group of 28 internationally renowned scientists led by Johan Rockström from the Stockholm Resilience Centre and Will Steffen from the Australian National University. This framework was first introduced in 2009 in the journal “Nature.” The purpose of the Planetary Boundaries framework is to define the limits within which humanity can safely operate to avoid catastrophic environmental change. It’s a crucial concept in sustainability and environmental management, often intersecting with permaculture principles which focus on creating sustainable and self-sufficient systems.

These are the Nine Planetary Boundaries and we already crossed six of them.

• Climate change: This boundary refers to the amount of greenhouse gases in the atmosphere that affect the global temperature and weather patterns. The safe limit is 350 ppm of CO2, but the current level is about 415 ppm. This boundary has been crossed and poses a high risk of destabilizing the Earth system2
• Biosphere integrity: This boundary refers to the diversity and functioning of life on Earth, both at the genetic and ecosystem levels. The safe limit is 10% of the pre-industrial extinction rate, but the current rate is 100-1000 times higher. This boundary has been crossed and poses a high risk of disrupting the biosphere and its services2
• Land-system change: This boundary refers to the amount of land that is converted from natural ecosystems to croplands, pastures, urban areas, and other human uses. The safe limit is 15% of the global ice-free land area, but the current level is 75%. This boundary has been crossed and poses a high risk of affecting the climate, water, and biodiversity2
• Freshwater use: This boundary refers to the amount of freshwater that is withdrawn from rivers, lakes, and aquifers for human purposes. The safe limit is 4000 km3 per year, but the current level is 2600 km3 per year. This boundary has not been crossed yet, but it is under increasing pressure due to population growth, irrigation, and climate change2
• Biogeochemical flows: This boundary refers to the cycles of nitrogen and phosphorus that are essential for life, but also cause pollution and eutrophication when they are altered by human activities. The safe limits are 35 Tg per year for nitrogen and 11 Tg per year for phosphorus, but the current levels are 150 Tg per year and 22 Tg per year, respectively. This boundary has been crossed and poses a high risk of affecting the biosphere and the oceans2
• Ocean acidification: This boundary refers to the decrease in pH of the ocean water due to the absorption of CO2 from the atmosphere. The safe limit is 0.1 units of change from the pre-industrial level, but the current level is 0.14 units. This boundary is very close to being crossed and poses a high risk of affecting the marine life and the coral reefs2
• Atmospheric aerosol loading: This boundary refers to the amount of tiny particles in the air that affect the climate, the clouds, and the human health. The safe limit is not well defined yet, but it is estimated to be between 5 and 8 on the regional dimming index. The current level varies by region, but some areas are above the safe range. This boundary is not crossed yet, but it is under increasing pressure due to industrial and agricultural emissions2
• Stratospheric ozone depletion: This boundary refers to the thinning of the ozone layer that protects the Earth from harmful ultraviolet radiation. The safe limit is 276 Dobson units of ozone concentration, but the current level is 283 Dobson units. This boundary is not crossed yet, and it is showing signs of recovery due to the global efforts to phase out ozone-depleting substances2
• Introduction of novel entities: This boundary refers to the release of new materials and substances into the environment that have unknown or harmful effects on the Earth system. These include synthetic chemicals, heavy metals, radioactive materials, plastics, and more. The safe limit is not well defined yet, but it is estimated to be zero or very low. The current level is unknown, but it is likely to be above the safe range. This boundary is not crossed yet, but it is under increasing pressure due to human innovation and consumption2

In summary, six of the nine planetary boundaries have been crossed, and one is very close to being crossed. The other two are not crossed yet, but they are under increasing pressure. This means that humanity is operating outside the safe operating space for the Earth system, and faces the risk of triggering abrupt and irreversible changes that could threaten the future of civilization234