Steve Pope Safaris

Semi-participatory Camping, Bushwalking, & Canoe Safaris

Global Cooling and Grassland Fire


Have anti Fire policies on the continents contributed to Global Warming? 

The booklet for the Global IGBP (International Geosphere – Biosphere Programme) Change Report No. 31 of the 2nd – 5th June 1993 held at Victoria Falls Zimbabwe, on page 8, informs us that soot particles from grassland fires contribute to global cooling. It is well documented that some volcanoes have emitted so much ash into the atmosphere that global temperatures have been lowered by 1 to 1½ Degrees Centigrade during the year after eruption. It has even been suggested that a “Mega Volcano” may have initiated an ice age. The booklet also states that African savannas have burned naturally and under human influence for thousands of years and that there is an annual accumulation of ozone-rich air in the troposphere over the subcontinent during the fire season and that preliminary calculations suggest that one sixth of the global tropospheric ozone production occurs in smoke plumes originating from African savanna fires. 

The National Geographic January 1980 vol 157 no.1 - in the article “The Tallgrass Prairie: Can It Be Saved?” by Dennis Farney on the map facing page 42 – “A sea of tallgrass covered 400, 000 square miles before farm, town, and road took nearly all of it.” On page 48 – Hulbert saw fuel for a long - overdue prairie fire. “Leave a prairie unburned and eventually you get a forest on it” he explained. Indians set fires to stampede game, and destroyed invading trees and shrubs in the process. But the number of prairie fires declined sharply with the white man’s arrival. As a result, “Woody plants now cover many areas that were never forested in presettlement times.”  Fire is a valuable tool. To redress the balance Hulbert has returned to the ancient tool of fire. The controlled fires he sets in spring devastate shrubs, trees, and early greening invaders like Kentucky bluegass.  The prairie grasses and wild flowers, generally deep rooted and still dormant, never feel them.

The October 1993 vol.184, no.4 National Geographic the article “Roots of the Sky” by Douglas H. Chadwick on Page 113 informs us that if there is no fire the conditions promote woody growth – people have been fighting fire for more than a century – if you go long enough without fire the prairie will be covered with trees – and on page 116 that the “Prairie State”, Illinois, has only 3500 acres of prairie left which is less than one ten- thousandth of the 37 million acres the settlers of the 19th century found. Millions of hectares of prairies that did not become woodland or forest inevitably turned into farmland, which also is not burnt. 

Grasses would have been the first type of vegetation to evolve. The growing points are below ground and within weeks of even a hot fire new shoots appear. They may have begun evolving while the earth was still cooling down. Volcanoes and lightning strikes would have started the original fires under which grasses evolved millions of years before man appeared. As the planet cooled some regions would have had less incidences of fire from natural sources – this would have allowed the evolution of woody plants and trees and leading to forestation in those regions. Since the cooling of the planet and evolution of man most fires have been anthropological where man has lit fires to provide grass for ease of hunting (the American Indian and in Africa), protection from dangerous game (in Africa) and providing grazing for livestock (the Masai). 

The prevention of fire policy for more than 100 years has resulted in the loss of more than 90 percent of the original grassland prairie in North America. This means that more than 90 percent of the global cooling soot particles and ozone enriching chemicals that entered the atmosphere from the prairies in the past do not do so any more.  

The same anti fire policies have prevailed in Africa and probably in the grasslands of South America and Australia

There are two types of fire –  

1)    Early Burning Cold fires in the winter months of May June and July in Zimbabwe. These fires burn when the grass stems are still moist and the low ambient temperatures ensure little damage to woody vegetation and seedlings and may even burn out during the night. 

2)    Late Burning Hot fires at the end of the dry season, just before the rains in late October early November. These fires burn when the grass stems are dry and with a high ambient temperature and invariably strong winds and are therefore much more intense and kill seedlings and young saplings. 

 Early burning is used as a means to establish woodland at the expense of grassland – “Early Burning in Brachystegia” by Fay Robertson. Early burning is policy in Zimbabwe, Zambia and Tanzania. Early dry season “cold “ fires allow bush encroachment and the establishment of woodland and greatly reduce the intensity of fires and the amount of smoke and chemicals released into the atmosphere, whereas late dry season “hot” fires inhibit woody growth and maintain grassland and contribute the most soot particles and ozone enriching chemicals. 

Have the anti fire policies imposed on the American and African continents and Australia, since colonisation, initiated the current global warming trend?  

Ice Ages have ebbed and flowed in cycles over hundreds of thousands of years.

Did the millions of square kilometers of grassland that burnt annually on all the continents gradually cause the global cooling that established an ice age?

 Once an ice age was established there may have been a decrease in the amount of grassland and consequent fires and so a phase of global warming would begin and the ice age recede. Eventually the grasslands and accompanying fires would be re established. Thousands of years later these grassland fires would cause another period of global cooling and a new ice age and so the cycles continued. 

If the current Global Warming has been caused by anti-grassland “hot” fire policies over the last 200 years then the consequences are serious because the prevention of late dry season “hot” fire has turned the grasslands that used to exist into woodlands and forests, which even if they could be burnt, do not contribute the same soot particles and chemicals, that grassland fires do. (NB -grass is the essential fuel required to burn woody plants - if there is no grass a fire will not burn). 

A worldwide effort to re-establish the grasslands and anthropological fire regimes that existed before the colonisation of the American, African and Australian continents might help stop the current warming and lead to a period of global cooling.