Wager between Julian Simon and Paul Ehrlich
"The face-off occurred in the pages of Social Science Quarterly, where Simon challenged Ehrlich to put his money where his mouth was. In response to Ehrlich's published claim that "If I were a gambler, I would take even money that England will not exist in the year 2000" - a proposition Simon regarded as too silly to bother with - Simon countered with "a public offer to stake US$10,000 ... on my belief that the cost of non-government-controlled raw materials (including grain and oil) will not rise in the long run.
You could name your own terms: select any raw material you wanted - copper, tin, whatever - and select any date in the future, "any date more than a year away," and Simon would bet that the commodity's price on that date would be lower than what it was at the time of the wager." ... Ehrlich and his colleagues picked five metals that they thought would undergo big price rises: chromium, copper, nickel, tin, and tungsten. Then, on paper, they bought $200 worth of each, for a total bet of $1,000, using the prices on September 29, 1980, as an index. They designated September 29, 1990, 10 years hence, as the payoff date. If the inflation-adjusted prices of the various metals rose in the interim, Simon would pay Ehrlich the combined difference; if the prices fell, Ehrlich et al. would pay Simon. ... Between 1980 and 1990, the world's population grew by more than 800 million, the largest increase in one decade in all of history. But by September 1990, without a single exception, the price of each of Ehrlich's selected metals had fallen, and in some cases had dropped through the floor. Chrome, which had sold for $3.90 a pound in 1980, was down to $3.70 in 1990. Tin, which was $8.72 a pound in 1980, was down to $3.88 a decade later. 
As a result, in October 1990, Paul Ehrlich mailed Julian Simon a check for $576.07 to settle the wager in Simon's favor.
Analysis of why Ehrlich lost
According to Paul Ehrlich's website: "In 1980, Julian Simon repeatedly challenged environmental scientists to bet against him on trends in prices of commodities, asserting that humanity would never run out of anything. Paul and the other scientists knew that the five metals in the proposed wager were not critical indicators and said so at the time. They emphasized that the depletion of so-called renewable resources--environmental resources such as soils, forests, species diversity, and groundwater--is much more indicative of the deteriorating state of society's life-support systems....Nonetheless, after consulting with many colleagues, Paul and Berkeley physicists John Harte and John Holdren accepted Simon's challenge in late 1980..."
Julian Simon won because the price of three of the five metals went down in absolute terms and all five of the metals fell in price in inflation adjusted terms  with both tin and tungsten falling by more than half (inflation adjusted). So, per the terms of the wager, Ehrlich paid Simon the difference in price between the same quantity of metals in 1980 and 1990 (which was $576.07). The prices of all five metals increased between 1950 and 1975, but Ehrlich believes three of the five went down during the 1980s because of the price of oil doubling in 1979, and because of a worldwide recession in the early 1980s.
Yet, it is significant that "All of the former's [Ehrlich's] grim predictions had been decisively overturned by events. Ehrlich was wrong about higher natural resource prices, about "famines of unbelievable proportions" occurring by 1975, about "hundreds of millions of people starving to death" in the 1970s and '80s, about the world "entering a genuine age of scarcity."
In 1990, for his having promoted "greater public understanding of environmental problems," Ehrlich received a MacArthur Foundation "genius" award." 
"[Simon] always found it somewhat peculiar that neither the Science piece nor his public wager with Ehrlich nor anything else that he did, said, or wrote seemed to make much of a dent on the world at large. For some reason he could never comprehend, people were inclined to believe the very worst about anything and everything; they were immune to contrary evidence just as if they'd been medically vaccinated against the force of fact. Furthermore, there seemed to be a bizarre reverse-Cassandra effect operating in the universe: whereas the mythical Cassandra spoke the awful truth and was not believed, these days "experts" spoke awful falsehoods, and they were believed. Repeatedly being wrong actually seemed to be an advantage, conferring some sort of puzzling magic glow upon the speaker." 
Simon offered to raise the wager to $20,000 and use any resources at any time that Ehrlich preferred, but the two were unable to reach an agreement on the terms of a second wager.
The proposed second wager
Understanding that Simon wanted to bet again, Ehrlich and climatologist Stephen Schneider counter-offered, challenging Simon to bet on 15 current trends, betting $1000 that each will get worse (as in the previous wager) over a ten year future period.
The trends they bet would continue to worsen were:
- The three years 2002-2004 will on average be warmer than 1992-1994.
- There will be more carbon dioxide in the atmosphere in 2004 than in 1994.
- There will be more nitrous oxide in the atmosphere in 2004 than 1994.
- The concentration of ozone in the lower atmosphere (the troposphere) will be greater than in 1994.
- Emissions of the air pollutant sulfur dioxide in Asia will be significantly greater in 2004 than in 1994.
- There will be less fertile cropland per person in 2004 than in 1994.
- There will be less agricultural soil per person in 2004 than 1994.
- There will be on average less rice and wheat grown per person in 2002-2004 than in 1992-1994.
- In developing nations there will be less firewood available per person in 2004 than in 1994.
- The remaining area of virgin tropical moist forests will be significantly smaller in 2004 than in 1994.
- The oceanic fisheries harvest per person will continue its downward trend and thus in 2004 will be smaller than in 1994.
- There will be fewer plant and animal species still extant in 2004 than in 1994.
- More people will die of AIDS in 2004 than in 1994.
- Between 1994 and 2004, sperm cell counts of human males will continue to decline and reproductive disorders will continue to increase.
- The gap in wealth between the richest 10% of humanity and the poorest 10% will be greater in 2004 than in 1994.
Simon declined the bet, and used the following analogy to explain why he did so:
"Let me characterize their [Ehrlich and Schneider's] offer as follows. I predict, and this is for real, that the average performances in the next Olympics will be better than those in the last Olympics. On average, the performances have gotten better, Olympics to Olympics, for a variety of reasons. What Ehrlich and others says is that they don't want to bet on athletic performances, they want to bet on the conditions of the track, or the weather, or the officials, or any other such indirect measure."