Unnatural Cycles: Anthropogenic Disruption To Health And Planetary Functions

Comment: Answers to reviewers; new or changed text in italics.

Reviewer 1
Line 26-30 provide reference.
Thank you for asking for further reference: we have added the following: 
Hydrological: Rodell, M,; Beaudoing, H.K.; L’Ecuyer, T.S.; Olson, W.S.; Famiglietti, J.S.; Houser, P.R. The observed state of the water cycle in the early twenty-first century. Journal of Climate 2015, 28, 8289-8318. doi:10.1175/JCLI-D-14-00555.1
Nitrogen: Gruber, N.; Galloway, J.N. An Earth-system perspective of the global nitrogen cycle. Nature 2008, 451, 293-296. doi:10.1038/nature06592
Carbon: Friedlingstein, P.; O'Sullivan, M.; Jones, M.W.; Andrew, R.M.; Hauck, J.; Olsen, A.; et al. Global Carbon Budget 2020. Earth Syst. Sci. Data 2020, 12, 3269–3340. doi:10.5194/essd-12-3269-2020, 2020.

Figure 1 unclear
Thank you for pointing this out. See below for our answer to the same pointy from reviewer 2.

73 to 76 divide the sentence
Thank you. We have divided the sentence (lines 77-80):
In addition, there are requirements for transport at various points. These contribute directly to poor air quality through vehicular emissions, and indirectly through break-down of vehicle parts such as tyres and brakes. All of these may lead to further health issues, including asthma and COPD.

Figure 2 unclear
We are unable to make changes to the diagram, as it has been reproduced from an authoritative textbook. Instead, text has been added iin two places, as below, which explains that Younger has illustrated the complexity of mining and hydrological activity. 
The figure caption (line 250) now reads:
The complex interactions and impacts of mining and chemical actions. 
The paragraph now reads (lines 258-259, new text in italics):
Waste materials from mining do not stay neatly packaged in the locality in which they are generated. Through a combination of windblow, leaching, and physical transfer (on tyres, etc) the unwanted pollutants move away from the mine sites [40,46–48]. As the waste enters the aquatic environment it may be transported several miles through surface water, and ultimately reach the sea. Younger (fig 2) has described the complexity of interaction between mined material, rock strata and the hydrological environment.

Reviewer 2
This is presented as a concept paper, it does not present research findings as such but takes an interesting approach to what we might consider unnatural feedback loops. The authors consider the lung disease unnatural cycle – which they articulate through the lense of an unnatural cycle with feedback loops that serve to reinforce (and in some cases amplify) negative problems. I found the article interesting. What it lacks in depth/detail is made up for by its accessible style. As a concept paper there is very little to disagree with.
Thank you for this encouraging assessment.

One comment on reading the paper was linked to an areas of simplification that might need further consideration - Whilst natural cycles should be maintained in dynamic equilibrium, as the authors note, what too of the concept of thresholds where a shift occurs to a new, but different, equilibrium. I wonder if this also needs to be acknowledged give the potentially chaotic period before the new equilibrium is established?
Thank you for this point, which needs further consideration, beyond our paper. However, we have added the following (lines 49-51): 
The resetting of thresholds in natural cycles, where a shift occurs to a new, but different, equilibrium, resulting in a potentially chaotic period before the new equilibrium is es-tablished, may be similar in some ways to an unnatural cycle, but is not pursued further here.

Other more general comments are listed below: 
Line 59 ‘in much the same way as the eruption of a volcano will bring about long-term geological change.’ I’m not sure I agree with this sentence as is not the volcanic eruption a consequence of long-term geological change?
Thank you for pointing this out. We have addressed this as follows (lines 61-64): 
Short-term anthropogenic activities may contribute to long-lasting environmental changes, and not always in a positive way, in much the same way as the  short term eruption of a volcano will bring about long-term geological change through deposition of ash, molten lava, and potentially through movement of tectonic plates.   

Figure 1 needs more emphasis on the inclusion of lung disease and not just asthma
Thank you for this perceptive comment; we have redrawn the figure to include wider issues of lung disease and also to address clarity issues raised by reviewer 1. 

Line 77 ‘Whereas many of the natural cycles are broken and need to be mended’ are they broken? This seems an overly strong  statement as I would argue many are impacted  or  perturbed rather than broken.
Thank you. We agree that many natural cycles are impacted and perturbed; in this way they are broken, but we have rewritten this sentence (lines 82-83): 
Whereas many of the natural cycles are adversely impacted and perturbed and need to be mended… 

Table 1 to what does 640  GP visits refer in row 1 – this number requires further contextualisation
Thank you for picking up on this. It should be $640 per visit.

Line 339 ‘of has COPD’ need to replace of with or
Thank you, we have corrected this typo (line 345).

Line 340 ‘We have focused upon (too)’ – do the authors mean (two)?
Thank you for questioning this. We did mean ‘too’. However, we have changed the sentence to avoid ambiguity. It now reads (lines 346-347): 
We have focused upon illnesses which are all too commonplace, yet which could be reduced as an ‘everyday’ presentation through better management: