Ellen agrees and Santiago disagrees, so this is the disagreement. Ellen’s argument does exactly this, using an estimated dollar value to rationalize protecting the biosphere. Santiago, though, says that economic value is not how we should justify protecting the biosphere.

Santiago agrees with this, but Ellen never disagrees. Ellen focuses on the value of the “services” provided by the biosphere, but doesn’t eliminate the possibility of a more important value.

Neither speaker talks about what would be the most effective way to ensure that the biosphere is urgently protected, so we can’t say that either Ellen or Santiago expresses an opinion.

Neither speaker makes this claim. Ellen accepts the idea of estimating this dollar value, and even Santiago doesn’t take issue with whether the calculation is realistic.

Santiago agrees with this, but Ellen doesn’t disagree. Ellen doesn’t talk at all about the implications of doing this calculation, or about what the biosphere’s most important value is.