@@ -19,6 +19,7 @@ Contributors are:
 -Timothy B. Hartman <tbhartman _at_ gmail.com>
 -Konstantin Popov <konstantin.popov.89 _at_ yandex.ru>
 -Peter Jones <pjones _at_ redhat.com>
+-Anson Mansfield <anson.mansfield _at_ gmail.com>
 -Ken Odegard <ken.odegard _at_ gmail.com>
 -Alexis Horgix Chotard
 
 
@@ -47,7 +47,7 @@
 execute_kwargs = set(('istream', 'with_extended_output',
                       'with_exceptions', 'as_process', 'stdout_as_string',
                       'output_stream', 'with_stdout', 'kill_after_timeout',
-                      'universal_newlines', 'shell'))
+                      'universal_newlines', 'shell', 'env'))
 
 log = logging.getLogger(__name__)
 log.addHandler(logging.NullHandler())
@@ -597,6 +597,7 @@ def execute(self, command,
                 with_stdout=True,
                 universal_newlines=False,
                 shell=None,
+                env=None,
                 **subprocess_kwargs
                 ):
         """Handles executing the command on the shell and consumes and returns
@@ -640,6 +641,9 @@ def execute(self, command,
             decoded into a string using the default encoding (usually utf-8).
             The latter can fail, if the output contains binary data.
 
+        :param env:
+            A dictionary of environment variables to be passed to `subprocess.Popen`.
+
         :param subprocess_kwargs:
             Keyword arguments to be passed to subprocess.Popen. Please note that
             some of the valid kwargs are already set by this method, the ones you
@@ -685,6 +689,7 @@ def execute(self, command,
         cwd = self._working_dir or os.getcwd()
 
         # Start the process
+        inline_env = env
         env = os.environ.copy()
         # Attempt to force all output to plain ascii english, which is what some parsing code
         # may expect.
@@ -693,6 +698,8 @@ def execute(self, command,
         env["LANGUAGE"] = "C"
         env["LC_ALL"] = "C"
         env.update(self._environment)
+        if inline_env is not None:
+            env.update(inline_env)
 
         if is_win:
             cmd_not_found_exception = OSError
 
@@ -106,6 +106,21 @@ def test_it_ignores_false_kwargs(self, git):
         self.git.version(pass_this_kwarg=False)
         assert_true("pass_this_kwarg" not in git.call_args[1])
 
+    def test_it_accepts_environment_variables(self):
+        filename = fixture_path("ls_tree_empty")
+        with open(filename, 'r') as fh:
+            tree = self.git.mktree(istream=fh)
+            env = {
+                'GIT_AUTHOR_NAME': 'Author Name',
+                'GIT_AUTHOR_EMAIL': 'author@example.com',
+                'GIT_AUTHOR_DATE': '1400000000+0000',
+                'GIT_COMMITTER_NAME': 'Committer Name',
+                'GIT_COMMITTER_EMAIL': 'committer@example.com',
+                'GIT_COMMITTER_DATE': '1500000000+0000',
+            }
+            commit = self.git.commit_tree(tree, m='message', env=env)
+            assert_equal(commit, '4cfd6b0314682d5a58f80be39850bad1640e9241')
+
     def test_persistent_cat_file_command(self):
         # read header only
         import subprocess as sp