diff --git a/app/Main.hs b/app/Main.hs
index 1c4f962..1a2c54e 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -202,9 +202,10 @@ loop loopAmount ps env opts = loop' loopAmount 0 ps env
       loop' loopAmount (curLoop+1) newPlants s
 
 data CLIOptions = CLIOptions
-    { environment :: Maybe FilePath
-    , logfile     :: FilePath
-    , verbose     :: Bool
+    { environment     :: Maybe FilePath
+    , logfile         :: FilePath
+    , verbose         :: Bool
+    , dumpEnvironment :: Bool
     }
 
 cliOptParser :: Parser CLIOptions
@@ -228,6 +229,11 @@ cliOptParser = CLIOptions
         <> short 'v'
         <> help "show 'gui' during process"
         )
+    <*> switch
+        (long "write-environment"
+        <> short 'w'
+        <> help "write environment used to $PWD/environment.json"
+        )
 
 cliopts = info (cliOptParser <**> helper)
                 (fullDesc
@@ -260,7 +266,7 @@ main = do
   enzs <- randomRs (0,length (possibleEnzymes env) - 1) <$> newStdGen
   let startPlants      = randomGenome 2 enzs (possibleEnzymes env) emptyPlants
   --writeFile "poison.twopi" $ generateDotFromPoisonTree "poison" 0.5 poisonedTree
-  LBS.writeFile "environment.json" . encode $ env
+  when (dumpEnvironment opts) $ LBS.writeFile "environment.json" . encode $ env
   when printEverything $ putStr "\ESC[?1049h"
   loghandle <- openFile (logfile opts) WriteMode
   putStrLn $ "logging to: " ++ logfile opts
diff --git a/simulation_am.ods b/simulation_am.ods
index b8e4b2e..965874b 100644
Binary files a/simulation_am.ods and b/simulation_am.ods differ
diff --git a/simulation_no_am.ods b/simulation_no_am.ods
index e619548..ce04890 100644
Binary files a/simulation_no_am.ods and b/simulation_no_am.ods differ